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Re: uBITX Display Emulation / Screen Capture
Thanks for the tip Jack. To compare a string literal, do you recommend using strcmp or strncmp ? e.g.? if (!strcmp(buffer,"d")) {? --or -- if (!strncmp(buffer,"d",11)) {? <-- this would appear to be more robust, and show that the first 10 chars + NULL string termination are being compared.? or some other way? Either works for this small test case. Rgds, Gary |
bitx20 3C SBL - Bandpass filter inductor issue
I've got this kit I've had around for 4 years and it is mostly working though there is an issue with the three inductors not "adjusting." The tuning plugs move just fine, but I have to put an absurd amount of pressure on them, then they start to pass RF. I've actually picked up stations after fussing with them, but I would like to know if anyone else had a similar issue with the bandpass filter and any guidance to correcting the lack of tunability. Thanks! -- Jason Pirok W4UNX |
Re: bitx-ver-3c LCD PIC processor code
#bitx20
#bitx20help
I think you missed what the man is saying. He's working with the original bitx20 kit that was around before the Raduino and uses an FLL board with a PIC and LCD display. The FLL also supplies stabilizing pulses to the analog VFO.? Greg, you need to message Sunil from to see if he can help you with troubleshooting your FLL board. He will be the best person to help with replacement parts as well. I recently bought a brand new FLL from his store not long ago. W4UNX? On Mon, Jan 11, 2021 at 7:21 PM Arv Evans <arvid.evans@...> wrote:
--
Jason Pirok W4UNX |
Re: uBITX Display Emulation / Screen Capture
Jack, W8TEE
Hi Gary: I would like to discourage you from using the String class in the Arduino environment. It can lead to fragmentation and other nasties. Try this an see if it works for your use: ??? char buffer[11]; ??? int eos; ??? // more of your code... ??? while (Serial.available()) { ??????? eos = Serial.readBytesUntil('\n', buffer, 10);??? // Read max of 10 chars ??????? buffer[eos] = '\0';?????????????????????????????? // Make it a string ??????? // continue processing as you wish... ??? } ?? This should work and still not fragment your limited memory. Jack, W8TEE ?
On Tuesday, January 12, 2021, 5:12:35 PM EST, Gary Anderson <gary.ag5tx@...> wrote:
The test was using Reed's code and replacing the ubitx_cat.cpp. Code space is at a premium.? I have extra flash space with the Optiboot bootloader. (32234 bytes used) output format of x,y,color was for a QND bitmap, and it matches.? Color codes also match. Rgds, Gary #include <Arduino.h>
#include <SPI.h>
#include "pin_definitions.h"
?
#define COLMAX 319
#define PAGMAX 239
?
void checkCAT(){
? ? String GetString;
? ? uint16_t R = 0;
? ? uint16_t G = 0;
? ? uint16_t B = 0;
?
? ? while (Serial.available() > 0) {
? ? ? ? GetString = Serial.readStringUntil(10); // 10 is a return
? ? ? ? if (GetString.equals("d")) {
? ? ? ? ? ? SPI.begin();
? ? ? ? ? ? SPI.setClockDivider(SPI_CLOCK_DIV4); // 4 MHz (half speed)
? ? ? ? ? ? SPI.setBitOrder(MSBFIRST);
? ? ? ? ? ? SPI.setDataMode(SPI_MODE0);?
?
? ? ? ? ? ? pinMode(PIN_TFT_CS,OUTPUT);
? ? ? ? ? ? pinMode(PIN_TFT_DC,OUTPUT);
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, LOW);
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2A); // CASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? ?//start
? ? ? ? ? ? SPI.transfer16(COLMAX); // stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2B); // PASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? //start
? ? ? ? ? ? SPI.transfer16(PAGMAX); //stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2E); // RAMRD
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer(0x0); // dummy
?
? ? ? ? ? ? for (int y = 0; y <= PAGMAX; y++){
? ? ? ? ? ? ? for (int x = 0; x <= COLMAX; x++){
? ? ? ? ? ? ? ? //capture 8 bit from SPI
? ? ? ? ? ? ? ? R = SPI.transfer(0x0) >> 3; // 5 RED
? ? ? ? ? ? ? ? G = SPI.transfer(0x0) >> 2; // 6 GREEN
? ? ? ? ? ? ? ? B = SPI.transfer(0x0) >> 3; // 5 BLUE
? ? ? ? ? ? ? ? Serial.print(x);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? Serial.print(y);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? //display as 16 bit in 565 format
? ? ? ? ? ? ? ? Serial.println((R << 11) | (G << 5) | B);? ? ? ??
? ? ? ? ? ? ? }
? ? ? ? ? ? }
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, HIGH);
? ? ? ? ? ? SPI.endTransaction();
? ? ? ? }
? ? }
}
-- Jack, W8TEE |
Re: uBITX Display Emulation / Screen Capture
The test was using Reed's code and replacing the ubitx_cat.cpp. Code space is at a premium.? I have extra flash space with the Optiboot bootloader. (32234 bytes used)
output format of x,y,color was for a QND bitmap, and it matches.? Color codes also match. Rgds, Gary #include <Arduino.h>
#include <SPI.h>
#include "pin_definitions.h"
?
#define COLMAX 319
#define PAGMAX 239
?
void checkCAT(){
? ? String GetString;
? ? uint16_t R = 0;
? ? uint16_t G = 0;
? ? uint16_t B = 0;
?
? ? while (Serial.available() > 0) {
? ? ? ? GetString = Serial.readStringUntil(10); // 10 is a return
? ? ? ? if (GetString.equals("d")) {
? ? ? ? ? ? SPI.begin();
? ? ? ? ? ? SPI.setClockDivider(SPI_CLOCK_DIV4); // 4 MHz (half speed)
? ? ? ? ? ? SPI.setBitOrder(MSBFIRST);
? ? ? ? ? ? SPI.setDataMode(SPI_MODE0);?
?
? ? ? ? ? ? pinMode(PIN_TFT_CS,OUTPUT);
? ? ? ? ? ? pinMode(PIN_TFT_DC,OUTPUT);
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, LOW);
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2A); // CASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? ?//start
? ? ? ? ? ? SPI.transfer16(COLMAX); // stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2B); // PASET
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer16(0);? //start
? ? ? ? ? ? SPI.transfer16(PAGMAX); //stop
?
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, LOW);
? ? ? ? ? ? SPI.transfer16(0x2E); // RAMRD
? ? ? ? ? ? digitalWrite(PIN_TFT_DC, HIGH);
? ? ? ? ? ? SPI.transfer(0x0); // dummy
?
? ? ? ? ? ? for (int y = 0; y <= PAGMAX; y++){
? ? ? ? ? ? ? for (int x = 0; x <= COLMAX; x++){
? ? ? ? ? ? ? ? //capture 8 bit from SPI
? ? ? ? ? ? ? ? R = SPI.transfer(0x0) >> 3; // 5 RED
? ? ? ? ? ? ? ? G = SPI.transfer(0x0) >> 2; // 6 GREEN
? ? ? ? ? ? ? ? B = SPI.transfer(0x0) >> 3; // 5 BLUE
? ? ? ? ? ? ? ? Serial.print(x);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? Serial.print(y);
? ? ? ? ? ? ? ? Serial.print(",");
? ? ? ? ? ? ? ? //display as 16 bit in 565 format
? ? ? ? ? ? ? ? Serial.println((R << 11) | (G << 5) | B);? ? ? ??
? ? ? ? ? ? ? }
? ? ? ? ? ? }
? ? ? ? ? ??
? ? ? ? ? ? digitalWrite(PIN_TFT_CS, HIGH);
? ? ? ? ? ? SPI.endTransaction();
? ? ? ? }
? ? }
} |
Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer
Gordon Same here.? Those integrated diode IC's are a big improvement but even ones from the same corner of the same die are probably not perfectly matched after they have been manually soldered onto a PCB.? Even for those it seems better to have a balancing network to insure we get the best balance after everything is assembled.? Maybe this is just a feel-good situation but part of optimizing a build is feeling good about how it went together and how it was adjusted after the build.? This seems especially true if the mixer is a 2-diode version instead of the full ring of 4 diodes. Arv _._ On Tue, Jan 12, 2021 at 2:40 PM Gordon Gibby <docvacuumtubes@...> wrote:
|
Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer
¿ªÔÆÌåÓýIn the old days, I think we used a potentiometer and maybe a variable capacitor to balance out these mixers. I¡¯ve got a Heathkit SB 102 that I soldered together as a high school kid, and it has four individual diodes and I remember nulling out the carrierSurely it can still be successful with all of the advanced semiconductors we have now.? On Jan 12, 2021, at 16:29, Bob Lunsford via groups.io <nocrud222@...> wrote:
|
Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer
It is always better to use diodes and transistors made on the same substrate. I remember replacing the PA transistor on an HW-8 with a dual transistor placed in parallel, doubled the power capability and since the? two transistors were on the same substrate, they were perfectly matched. If an IC can be found with four diodes, then finding matched diodes will not be required, if done on the same substrate ... IF such a thing exists. Bob ¡ª KK5R
On Tuesday, January 12, 2021, 8:09:17 AM EST, Cristian Radulescu via groups.io <criradul2001@...> wrote:
Hi all, Sorry to barge in like this. 12-13 years ago when I assembled my first, ugly style, BitX, I remember experimenting a lot with these mixers. What I found is, one can not match the matched mixer rings that exist, produced by various companies. What I ended up using was a diode ring IC "extracted" from a Motorola CP040 or GP300 VHF handy placed under a small shield close to the receiver part, between two trifilar transformers (obviously a mixer configuration), 8 pin IC chip produced by NEC or JRC. I am sure one can recover boards from these old handies for parts recovery. I had excellent results with it. 73's de YO3IAZ, Cristian
On Tuesday, January 12, 2021, 02:18:30 PM GMT+2, Loris IW4AJR via groups.io <lorisbollina@...> wrote:
Hi Rafael, It will not be easy to combine four diodes, but I have to buy the BAT41s, while I have the HP2835s in the drawer (at least forty) ... I hope to be able to find two groups of 4 diodes at least very similar.
The HP gave a margin of plus or minus 20mV of Vf between two diodes in match pair, is this an acceptable term? that is, what can be the maximum deviation between two diodes for a match pair?
On Tue, Jan 12, 2021 at 12:37 PM, <rafaelgcpp@...> wrote:
Loris, -- IW4AJR Loris |
Re: uBITX Display Emulation / Screen Capture
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On Jan 12, 2021, at 12:10 PM, Gary Anderson <gary.ag5tx@...> wrote:
|
Re: QUESTION for All - EASY BITX - HP 2800 series Schottky Diodes for Mixer
Over the years I have used my own matched diodes in mixers.? Matching is usually at a fixed current with a high impedance VOM measuring forward voltage drop.? On a few circuits I generated forward and reverse current (leakage) curves at DC, and at RF but did not see much gained by excessive measurement. Key for me has been matching the "knee point" where the diodes go into conduction, and matching the leakage curve if the diodes will be subject to high RF levels. Arv _._ On Tue, Jan 12, 2021 at 3:56 AM Loris IW4AJR via <lorisbollina=[email protected]> wrote:
|
Re: TFT Display Interfacing
This anecdote certainly illustrates that Jack is not dumb.
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In fact, he talks quite a bit.? ?;-) Jerry, KE7ER On Tue, Jan 12, 2021 at 10:40 AM, Arv Evans wrote:
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Re: TFT Display Interfacing
Old people did not get old by being dumb! _._ On Tue, Jan 12, 2021 at 9:47 AM Jack, W8TEE via <jjpurdum=[email protected]> wrote:
|
Re: Spectral analyser
I've been using a SDR dongle as a 'poor man's spectrum analyzer' for a few years now.? The one I have covers up to a 1 Mhz slice of the spectrum at a time (up to around a Ghz), although I can also zoom in to a few hundred hz, and with a upconverter mixer it works well with HF.? It's a bit frustrating if you want to look for spurious signals from a radio that may be beyond the 'window', but that also can be done.? (You just have to move the center frequency up through the range you're interested in.)
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I've also used it to check deviation of voice and PL tones on a FM rig.? Knowing a bit of theory comes in handy when working on circuits - a balanced bridge can be used to determine a lot of characteristics about a signal or device, and you can easily 'trick' equipment to measure things that aren't what the equipment is designed for - for instance, using an antenna analyzer to determine the characteristics of a toroid core.? (They also can be tricked into giving information about capacitors and tuned circuits.) I'm thinking about getting one of those tinySA units, once I can get enough money together, although I'd want to check the maximum frequency spread that it can display at one time.? I've also eyeballed some of the transistor curve tracer kits, but none of the affordable (for me) units really would do the job - and one of the more common kits could fry a component you're testing if hooked up wrong. Bob N4FBZ On 1/11/21 7:52 PM, Arv Evans wrote:
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Re: uBITX Display Emulation / Screen Capture
On Sat, Jan 9, 2021 at 04:26 AM, Mark Erbaugh wrote:
Alternatively, I considered adding a routine to my sketch to dump the ILI9341 screen memory to the serial port, but I can't find a way to read the screen memory. Can that be done?Hi Mark, Yes it can be done.??0x2E command is RAMRD.? If anyone is interested in a c function to dump screen memory, I can post? c code that outputs x,y,565color. The starting program was Reed's V6 code. Rgds, Gary |
Re: TFT Display Interfacing
Jack, W8TEE
I have so much similar stuff that the XYL says she turns on her "cwap filter" when I talk. I love trivia! One time I was at the airport and a nice elderly lady was running the Information booth. I walked over to her and asked: me: "Is this the Information booth?" granny: "Why, yes it is, Dearie. What can I help you with?" me: "What's the capital of Nepal?" granny: "What?! I have no idea!" me: "Well, what kind of information booth is this?" I started walking away and she called out: "Well, what's the capital?" I answered: "Kathmandu", whereupon she asked me to spell it and she wrote it down! Fast forward about five months and I'm at the airport again. Sure enough, there's granny at the Information booth. I walked up and asked: "What's the capital of Nepal?" She looked up, shook her finger at me, smiled, and said: "Just a minute" whereupon she went rummaging through a drawer, retrieved a piece of paper, and proudly called out: "Kathmandu!" Ya gotta love her... Jack, W8TEE
On Tuesday, January 12, 2021, 11:30:05 AM EST, Dean Souleles <dsouleles@...> wrote:
On Tue, Jan 12, 2021 at 08:51 AM, Jack, W8TEE wrote: some TFT display drivers invert the color and the complement operator fixes it.Excellent tribal knowledge and good to know next time I think a display is defective. Dean -- Jack, W8TEE |
Re: TFT Display Interfacing
Jack, W8TEE
Looks good! I just know that some TFT display drivers invert the color and the complement operator fixes it. When I saw the light gray background, I thought that might have been an issue. Never mind! :>) Jack, W8TEE
On Tuesday, January 12, 2021, 8:42:27 AM EST, Dean Souleles <dsouleles@...> wrote:
On Mon, Jan 11, 2021 at 04:54 PM, Jack, W8TEE wrote: The colors look a little oddHi Jack, Here's a color corrected image done using Adobe Lightroom. The phone's software gets confused by the color of the ambient room light and the blue cast of the screen. When I used the compliment color, by the way, all I got was a gray background. (In one of my other lives I am a professional photographer so I should know better. Check out www.dsoulphoto.com sometime) Dean KK4DAS
?
-- Jack, W8TEE |
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