Microcontroller Programming

Anybody have experience with this? Where should I start?

I'm starting a project that would connect a RAMPS board to a secondary microcontroller. I'm looking to make it talk back through to the arduino with data from sensors and switches. The main purpose of this is to be able to flash this board with custom firmware that would allow for custom hardware on the printer. I know there is auxiliary pins on the RAMPS board but I want more throughput, need it actually.

I apologize if this isn't worded correctly or if it's vague.
PM me if you want.

The PCF8575 i2c i/o Expander seems purpose-built for your needs. You could use it to add a bunch of inputs to your setup and talk to it using i2C from the arduino without the complexity of a secondary custom-programmed microcontroller.

It's actually the arduino that you want to be communicating with. RAMPS is the shield. There might be plenty of pins available to do what you need. Everything on the arduino (and RAMPS for that matter) that doesn't have anything plugged in is fair game.

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Originally Posted by KDog

It's actually the arduino that you want to be communicating with. RAMPS is the shield. There might be plenty of pins available to do what you need. Everything on the arduino (and RAMPS for that matter) that doesn't have anything plugged in is fair game.

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I'm just echoing what KDog is saying here. Check out this thread: http://3dprintboard.com/showthread.p...ltipanel-Users In this thread a switch is wired up so the firmware has confirmation of when to continue after a filament change.

It is for a different Arduino board (a PrintrBoard) but everything still applies. All of those connection pins can be wired up to what ever you want.

One of the things on my project list is to get the code published that lets you connect up a volt meter to a random pin on your Arduino board and let the software find it. That helps make the firmware interface a little easier.

I believe I will be needing more pins then what is available in for the Aux pins.

I appreciate both the replies. Helpful.

I'm not sure how many pins you need but keep in mind, for instance, that if you are only using four of the stepper drivers on RAMPS, you can reprogram most of the pins on the fifth stepper. Take a look at the pins.h module in the firmware for an idea exactly how many pins we are talking about. I've not personally done this before so am not a good resource in this respect.

I thought I posted a reply but I have no idea where it went.

So I will try and recreate my masterpiece.

It's actually for a developers board, we are creating a printer that would allow for modification/attachments both in hardware and software. So, I will be leaving that 5th extruder open for 'play' for our developers. It did come to mind though, how many open pins that could be used when a RAMPS board is fully loaded. This pretty much leaves a few pins near your endstops as well as the auxiliary areas. We want to be able to allow the developers to have a dedicated microcontroller to develop on and that would attach later to the printer hardware. I could use the arduino, but that would require a constant update in firmware and that's not something we want to do at all. There are a few different avenues and we think we have a good direction now.