Learn Arduino?

vk3vsm

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I have an ESP32 sitting here on the bench , have been trying to work out for a while what to do with it
 

VK3ZYZ

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I have been playing with this led matrix code uploads fine but this is all I get any ideas??
Are you using the specified pins? It does make use of the SPI hardware I believe.
Looking at the picture, I'm unsure of your power connections.
The LED panels I have run on 5V only and it does look like you have maybe 12V connected as the Arduino barrel jack power seems to be the same as the panels. And the Arduino barrel jack needs to be at least 7V, not 5V.
Your Arduino will run ok on the laptop USB power but the LED panels will not.
Can you please clear up the connections?
 
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VK3ZYZ

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VK3ZYZ

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These may be a good board to play with.
1699218293175.png

Aliexpress price $13 +$8 postage.

Have a look at this video. The guy in it has put a lot of work into getting a community going and has produced docs and code examples for this board. He does make a comment that there are other similar boards around so if you get one, check it is the correct one to suit the info.


I think it could be a very fun board to play with. Maybe even run a radio synthesizer?
 

VK3ZYZ

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One of the useful devices to use in an Arduino installation is a rotary encoder. You will se them in almost all my VFO designs for instance.
Here is a pretty good video explaining a couple of versions.

 

VK3ZYZ

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Here is a neat H bridge for motor driving that is very affordable, at under $15 each from the normal on line stores.
It is rated at 6 to 27V, and 30A (43A Max) so can drive quite large loads.
These were mentioned in the video refereed to in post #56.
1719540370865.png

Here is an article on driving them from an Arduino.
1719541059639.png

I will bring some along for the next SADARC meeting.
 
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VK3YNV

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I have used those modules, I used them to repair a battery powered lift trolley. They worked pretty well.
 

VK3ZYZ

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I'm having a go at writing a non-3D printer bit of code for this board...
It has all of the Arduino 2560 plus a lot more and just for under $35. Not at all bad!

You get 4 x stepper drivers on board. And if you are game, there is space for a couple more to be fitted.
 

VK3ZYZ

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As an example of recycled parts, here is a push button assemble from an old TV. It even had a plug to suit the hot bed temperature input "J6".
Photo on 18-1-25 at 4.33 pm.jpg

Test code....

#define T_Bed A10 // J16 pin 1
int ButtonPress = 0;

void setup() {
Serial.begin(9600);
}
void loop() {
ButtonPress=analogRead(T_Bed);
Serial.println(ButtonPress);
delay(1000);
}

The values are...
No button = 1023
AV/TV = 953
Menu = 997
V- = 892
V+. = 800
CH- = 560
CH+ = 0

Now I am hunting through my scrapped devices for suitable connectors for the limit switch inputs and the Fan "J10".
I will also be able to install FET "Q13" an the LED connector "J11" to expand the outputs.
There are the un-used U and U2 positions as well as the 6the stepper motor driver poets that I may try for a bit banged I2C port later.
 

VK3ZYZ

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I have modded the PCB. It was hndy to have an un-used motor position as that fits the I2C JST 4 pin connector.
IMAG0083.JPG

A wire comes from R143 to connect the missing SDA.
And here are the others from H2 to connect the SCL and +5V. The gnd just comes from the close by copper.
IMAG0081.JPG


And it works :)
1737192485773.png


And a small display...
Photo on 18-1-25 at 8.40 pm.jpg
 
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VK3ZYZ

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I reckon it was an artwork error as the pin that is the SDA is labeled "LCM_RS" and the other "LCM_xx" pins go to the H2 connector for the display. And the LCD does need the RS signal so they changed the code to suit the pin "EC_PRESS" that was there instead. And that pin on the processor is next to the one that they should have used.
 
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VK3ZYZ

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1737776466502.png

I've modified a design by https://www.thingiverse.com/tonyrod as a good setup for learning Arduino.
The breadboards I have do not fit so that may be an extra version later.
 
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