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Re: lcd 3.5 display help sought
Jack Purdum
Some time ago I posted a photo of a 2.4" mcufriend tft display I hope to integrate into my rig. I have also tried it with the 3.5" display and it works fine, but is not scaled correctly. It would be a lot of work, but the code could be configured to auto-scale at runtime after reading the display ID.? Jack, W8TEE From: Art Olson via Groups.Io <olsonaj6927@...> To: [email protected] Sent: Sunday, February 5, 2017 9:36 AM Subject: Re: [BITX20] lcd 3.5 display help sought Sent from my iPhone 3.5. Ordered a 2.8 and should be here this week. 3.5 supports mcufriend. Initially ran examples to make sure it would work under mcufriend. Looked thru the sketches to see where to change the LCD model - no luck.? Art
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Re: lcd 3.5 display help sought
¿ªÔÆÌåÓýSent from my iPhone 3.5. Ordered a 2.8 and should be here this week. 3.5 supports mcufriend. Initially ran examples to make sure it would work under mcufriend. Looked thru the sketches to see where to change the LCD model - no luck.? Art On Feb 5, 2017, at 7:48 AM, G4NQX <tasmod@...> wrote:
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Re: Possible PA low output problem.
Only one problem - except for folks who were "grandfathered in" with those licenses and never wend any further, there is no such thing as a "Novice" license any more; just Technician, General, and Extra. Rich KC8MWG On Sunday, February 5, 2017 7:56 AM, Paul Chebi <paul.chebi@...> wrote: My suggestion would be get a novice licence to start. Kb6nu has excellent courses for all exams. That would be a good introduction to what you're getting into.? Paul kk4ptv
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Re: lcd 3.5 display help sought
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On Feb 4, 2017, at 10:27 PM, Jack Purdum via Groups.Io <econjack@...> wrote:
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Re: LCD Contrast
Mvs Sarma
As I had already indicated , it works with 1K resistor from pin3 to ground of LCD. Your pot wiring does the same. Instead, Even a single 1N4148 from pin 3 to ground (cathode to gnd) works. On Sunday, 5 February 2017 3:02 PM, G4NQX <tasmod@...> wrote: Talking of lcd contrast. I usually wire up as a voltage divider as I've always known it to be.? First pic. By accident on the breadboard I plugged the 5v wire in an empty row,
so the pot didn't have a 5v supply. Pic 2.? To my surprise it works ok
with no problems. I've searched for an answer as to any harm but most results say voltage divider.? Anyone really know why pic 2 is considered wrong ? -- Rob G4NQX |
Re: LCD Contrast
G4NQX
Why does the answer come up as you post !! OK i found what I was looking for.? The contrast pin is current driven, not voltage and requires 200uA to be drawn to keep the contrast just so.? Grounding the pin via a variable resister brings the current draw up to requirements and provides contrast.
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LCD Contrast
G4NQX
Talking of lcd contrast. I usually wire up as a voltage divider as I've always known it to be.? First pic. By accident on the breadboard I plugged the 5v wire in an empty row,
so the pot didn't have a 5v supply. Pic 2.? To my surprise it works ok
with no problems. I've searched for an answer as to any harm but most results say voltage divider.? Anyone really know why pic 2 is considered wrong ?
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Re: Group Uploading
G4NQX
The moderator or owner of the group can set the permisssion to upload files to 'ALL' in the group.? This was reset at maintenance and could be reset back. HANS ,? ASHHAR ???? Where are youuuu........ Please could we have upload back.? We promise to be good boys or girls ! Honest !
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Re: Click on keying ptt
Interestingly, I did the audio gain change (removing the cap that's between pin 1 and 8 on the lm386) and didn't like how the audio sounded on my speaker. When I put the cap back in, suddenly the chirp almost gone. It had been quite significant before.?
-- Ryan Flowers KC7RYS? |
Re: Possible PA low output problem.
On Sat, Feb 4, 2017 at 12:47 pm, Jerry Gaffke wrote:
How would you solve the issue of some new ham with a voltmeter and a Bitx40 that doesn't quite work? If I were to advise a new ham with just a voltmeter, I'd tell him he needs to learn to walk before he can run, and that if he wants to get into home brewing he should start with something less challenging--for instance a DC receiver kit with a good track record of successful builds. Then maybe get an Arduino and monkey with that a while. Get it to display his call sign on an LCD, play with one of the ADC channels to read the value of a pot, stuff like that. Then get an Si5351 board from Adafruit or Etherkit or QRP Labs and get it to make some RF. He can verify it's working by using the receiver he built. By now, he (or she) is getting excited because there's been some accomplishment feedback (always positive, never negative) and some sense of making headway. So now he has a signal source and he knows a little MCU programming. Now maybe he can make a simple diode peak-detector type RF probe, and if he wants he can use the ADC in his Arduino to display the probe's reading (compensated in software for the non-linearity of the diode). I suppose he could even get an AD8307 and read the output of that with his Arduino (once he learns a little about logarithms--a Wikipedia article will do for starters). In the meantime, he's reading everything he can get his hands on about common-emitter biasing, double-balanced mixers, low pass filters, and the difference between resistance and reactance. Before he's hardly aware of it, he's off and running. He might buy one of those cheap-but-good-enough LC meters from China, and if he was still taking my advice I'd suggest he consider springing for an inexpensive oscilloscope--even an old analog one. This will kick his experimenting, testing, and troubleshooting capabilities into high gear.He'll at least know he'll need an SWR/Wattmeter and he might even put one together. They're nice, simple little projects. *Now* he can take the BitX40 off the shelf and know enough and be equipped enough to make a go of it, and in place of newcomer frustration and discouragement will come some real satisfaction.? That's how I would solve the problem of some new ham with a voltmeter and a Bitx40 that doesn't quite work. 73, Todd K7TFC |
Click on keying ptt
Hi bitxers,
Some have said they hear a click or perhaps a chirping on keying ptt, my bitx40 is no exception. When the ptt is pressed, the relay Rly1 is activated first, the +12tx line is enabling the microphone amplifier Q12 before rx audio Q16 has time to be disconnected by Rly2 (contacts M1 & M2) , therefore the microphone amplifier is active before the transmitter switching has completed hence a burst of feedback. If you delay power to the microphone amplifier allowing Rly2 to settle the "chirp" which is audio feedback does not occur. As a test I disconnected resistor R127 which provides power to Q12 microphone amplifier and inserted a 2n7000 fet as a switch inline with r127 with a RC delay on the gate, chirp has now gone, it's not the most elegant hack so hope some one can came up with a better solution. best 73 Alf vk2yac |
Re: adjusting the contrast on the LCD
He speaks of the LCD that came with the Radiuno. It was broken and replaced. As far as
I know, none of the lcds come with the contrast pot mounted on the lcd itself. I am sure there are some somewhere... The contrast pot is mounted on the Radiuno board next to the mcu. It is mounted on top of the board and is hard to adjust with the LCD in place. It really should be accessible from the bottom of the board. I made up a universal mounting plug-in board for breadboarding with a contrast pot, a 7805 filtered supply, and male and female headers so that I could use any lcd (except those with double row connectors), All the pins are brought out so that they are accessible from the breadboard. It's pretty handy. john AD5YE |
Re: adjusting the contrast on the LCD
Yes It is the same pot., Jack. all the best On Sun, Feb 5, 2017 at 9:08 AM, Mvs Sarma <mvssarma@...> wrote:
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Regards
Sarma ? |
Re: adjusting the contrast on the LCD
I generally manage with a 1K resistor or a single 1N4148 diode , with cathode facing ground. ?So far it has been working well for me. I do use model JHD162? modules.On Sun, Feb 5, 2017 at 9:01 AM, Jack Purdum via Groups.Io <econjack@...> wrote:
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Regards
Sarma ? |
Re: adjusting the contrast on the LCD
Jack Purdum
Most have a square pot on the back of the display. Not so with yours? Jack, W8TEE From: "davidzdeb@..." <davidzdeb@...> To: [email protected] Sent: Saturday, February 4, 2017 8:16 PM Subject: [BITX20] adjusting the contrast on the LCD I had to replace the LCD that came with the radio.? The new LCD has its contrast set too high.? Does anyone know how to change this?? Is it the blue and white pot next to the arduino??
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Re: lcd 3.5 display help sought
Jack Purdum
The four push buttons are used to control the frequency and its increment. One button allows you to move the cursor above the field that you wish to change. When you get it above the field that you wish to change, you push a button to set it to that field. The encoder can then be rotated to change the field. Truth is, that's a pretty clunky way to do it. In fact, the only reason is because that's the way the VFO code is set to work.? I use a process that I call Fast Tune. When you are just "tuning around", you rotate the encoder at a fairly slow rate and the frequency changes at a rate set at the current increment value. Let's assume it's 100Hz. If I tune slowly, like you do when you are zeroing in on a frequency, each detent of the encoder is +/- 100Hz, depending on CW (+) or CCW (-) rotation. But suppose you want to move from 7.280 to 7030 to listen to CW. In the video, you're going to have to do a bunch of button pushes to change it to a large increment (e.g., 10KHz) and then, when you get near the CW band, more button pushes to drop the increment back to 100Hz so you can zero in on the frequency you want. With Fast Tune, as soon as you start moving the encoder shaft rapidly (and you can define in software what "rapidly" is), the software senses the rate of turn on the encoder and immediately and automatically changes the increment to 10KHz (or whatever rate you have set in the code). Keep turning it quickly and the increment stays at 10KHz. However, as you approach your target frequency and you slow the turn rate down, the software senses that and drops the increment back to the "slow" rate of 100Hz (or whatever you have set it to). The default tune rate can even be changed at runtime via an encoder shaft press. No more press-a-button-move-to-the-digit-rate-button-press-rotate-the-encoder-to-the-frequency-button-press. Just move and go.? If I were you, I'd use Fast Tune in a heartbeat. The code for Fast Tune can be found in my article in the April issue of QRP Quarterly. Jack, W8TEE From: Art Olson via Groups.Io <olsonaj6927@...> To: [email protected] Sent: Saturday, February 4, 2017 5:23 PM Subject: [BITX20] lcd 3.5 display help sought I have been following PD8W (Willem) progress on his build out of a lcd display/si5351. His code and hardware are listed at PD8W.com. After some hard work I have the display working - and looks like his does on his web site. I am at the point where he is using momentary pushbuttons to cycle selections from the screen however am a bit lost as to how the buttons are actually wired up. I sent him a couple of requests for help but he must be out of town as I haven't gotten and feedback. Could someone take a look on his web page to see what I need to do? The sketch is also there and like I said it compiles. My first issue to overcome what understanding how to wire the lcd and found that in the mcufriend ino. Woohoo the display showed up on the lcd. Let me know if you need anything further. Note - I did hook it up to the bitx and the encoder does change freqs so that part is also working 73 Art |
Re: Group Uploading
Only one of the out of 6 I belong to show the UPLOAD button. 73 Ken On Sat, Feb 4, 2017 at 8:36 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
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