Hindsight is always 20/20.......

Yes, but foresight is less common. See my posts #152 and #156.

Edited to add: Don’t get me wrong, I think your design is wonderful, for an industrial design. I just don’t think it was the right thing for this inexperienced hobbyist. I think you will save everyone a lot of time if you have him ship you the boards and you develop the software and send them back.

 

Yes, but foresight is less common. See my posts #152 and #156.

Edited to add: Don’t get me wrong, I think your design is wonderful, for an industrial design. I just don’t think it was the right thing for this inexperienced hobbyist. I think you will save everyone a lot of time if you have him ship you the boards and you develop the software and send them back.

I think this is still a totally do-able project. I really like the boards and the format that we have decided to use. I'm sure we will figure this out!!!!

 

Don't get discouraged. I2C devices work well, but can be a pain in the butt to use the first time you use them. There are a number of things that have to be right to see anything happen.

From the questions asked, I think your young helpers just need a little understanding of the details. Microchip didn't help matters by combining the datasheet for essentially two different devices.

The key here is that we have MCP23017 port expanders using the I2C interface.* Ignore anything about the MCP23S17 and SPI interface.

The get started, it might be easiest to get an MCP23017 breakout board like this one where it's easy to check the port pins and you're not tied to the scoreboard. First master the chip, then work on how it controls the scoreboard.

This tutorial from Adafruit should be helpful. There are many good examples online.


*Do check that there actually are MCP23017 chips on the boards and not MCP23S17 chips.

 

Don't get discouraged. I2C devices work well, but can be a pain in the butt to use the first time you use them. There are a number of things that have to be right to see anything happen.

From the questions asked, I think your young helpers just need a little understanding of the details. Microchip didn't help matters by combining the datasheet for essentially two different devices.

The key here is that we have MCP23017 port expanders using the I2C interface.* Ignore anything about the MCP23S17 and SPI interface.

The get started, it might be easiest to get an MCP23017 breakout board like this one where it's easy to check the port pins and you're not tied to the scoreboard. First master the chip, then work on how it controls the scoreboard.

This tutorial from Adafruit should be helpful. There are many good examples online.


*Do check that there actually are MCP23017 chips on the boards and not MCP23S17 chips.

We are on it!!!

 

Yes, but foresight is less common. See my posts #152 and #156.

This problem is a minor issue, learning how to control an I2C port expander. Once control of the outputs is mastered, the rest is simple.

There would have been a similar learning curve with neopixels, plus many physical issues to overcome as well.

 

https://drive.google.com/file/d/1XbtzWI4m331Q2azw3-jy93eBOr8SVJu8/view?usp=sharing

 

My best advice is to get an MCP23017 breakout board and figure out the chip FIRST. Like I said, try some of the examples. Let's troubleshoot one part at a time.

The pins to the digit board will be at +12v when there is power to the digit board and the LEDs are off. The MCP2307s provide a ground connection to those lines to turn the LEDs on.

If you short from the digit board terminals to the common of the 12 volt supply, the LEDs will be illuminated. If not, the bulbs are in backwards or there's a wiring mistake.

 

My best advice is to get an MCP23017 breakout board and figure out the chip FIRST. Like I said, try some of the examples. Let's troubleshoot one part at a time.

The pins to the digit board will be at +12v when there is power to the digit board and the LEDs are off. The MCP2307s provide a ground connection to those lines to turn the LEDs on.

If you short from the digit board terminals to the common of the 12 volt supply, the LEDs will be illuminated. If not, the bulbs are in backwards or there's a wiring mistake.

I will pass it on!!!

I can get bulbs to illuminate if I run a jumper wire from the body of the scoreboard to 1-16 on the outputs.

 

My best advice is to get an MCP23017 breakout board and figure out the chip FIRST. Like I said, try some of the examples. Let's troubleshoot one part at a time.

The pins to the digit board will be at +12v when there is power to the digit board and the LEDs are off. The MCP2307s provide a ground connection to those lines to turn the LEDs on.

If you short from the digit board terminals to the common of the 12 volt supply, the LEDs will be illuminated. If not, the bulbs are in backwards or there's a wiring mistake.

Is this the same as a breakout board?
https://www.amazon.com/dp/B07P2H1NZG?psc=1&ref=ppx_yo2ov_dt_b_product_details

 

Yep.

 

The get started, it might be easiest to get an MCP23017 breakout board like this one where it's easy to check the port pins and you're not tied to the scoreboard. First master the chip, then work on how it controls the scoreboard.

This tutorial from Adafruit should be helpful. There are many good examples online.


*Do check that there actually are MCP23017 chips on the boards and not MCP23S17 chips.

 

Jon, not sure if you do any programing, but would it be prudent to send you the current program to see if there are any errors? I don't know enough about programing to see what is what.

 

What we're trying to do here isn't difficult. Using I2C chips can be a pain in the butt because if any of the details are wrong, nothing happens.

Programming Arduinos is not my forte, but as I have suggested, get an MCP23017 breakout board and install the Adafruit MCP23017 library and play with their examples. Give that an honest try.

Please VERIFY that you have MCP23017 chips installed on the boards (NOT MCP23S17).

Please use a breakout board completely removed from the scoreboard to get code working to control the MCP23017. Ignore everything that says it's for the SPI MCP23S17 version. We are using I2C protocol on the MCP23017 only.

The example code WILL WORK if:

● The correct I2C address is set in the code (i.e. the chip address set on the breakout board by jumpers matches the I2C address specified in the code).

● The I2C SCL and SDA lines have 4.7k pullup resistors to 5 volts – these are probably installed on a breakout board but may need to be enabled by jumpers.

 

What we're trying to do here isn't difficult. Using I2C chips can be a pain in the butt because if any of the details are wrong, nothing happens.

Programming Arduinos is not my forte, but as I have suggested, get an MCP23017 breakout board and install the Adafruit MCP23017 library and play with their examples. Give that an honest try.

Please VERIFY that you have MCP23017 chips installed on the boards (NOT MCP23S17).

Please use a breakout board completely removed from the scoreboard to get code working to control the MCP23017. Ignore everything that says it's for the SPI MCP23S17 version. We are using I2C protocol on the MCP23017 only.

The example code WILL WORK if:

● The correct I2C address is set in the code (i.e. the chip address set on the breakout board by jumpers matches the I2C address specified in the code).

● The I2C SCL and SDA lines have 4.7k pullup resistors to 5 volts – these are probably installed on a breakout board but may need to be enabled by jumpers.

We just got the breakout board, I will confirm later today what chip is installed.

 

The chip is the correct chip

 

This sort of difficulty is why I suggested a non-software type of arrangement.

 

This sort of difficulty is why I suggested a non-software type of arrangement.

Thanks for your input. It's very helpful.

 

We were able to run the program and get an LED to light up using the breakout board. We are going to try to get 16 to light up in a sequence next.

 

This sort of difficulty is why I suggested a non-software type of arrangement.

Opamps - ?

ak

 

We were able to run the program and get an LED to light up using the breakout board. We are going to try to get 16 to light up in a sequence next.

Excellent. That's the first step. The rest should be simple!