Help with "DMX Shield for Arduino (RDM Capable)"

Hello guys,

I'm planning buying a shield to get extended functionality to my Arduino Mega. Here is the link to the shield: https://www.tindie.com/products/Conceptinetics/dmx-shield-for-arduino-rdm-capable/

In the description of the shield, it says this:

Since the library uses the Arduino's primary USART it is not possible to use it together with the Hardware Serial libraries in your project since that will cause conflicting ISR (Interrupt service routine) routines.

Can anyone explain what that means?

Best regards Nelly

Not without seeing a link to the datasheet for the shield

…R

This is the only information available about the shield: https://sourceforge.net/p/dmxlibraryforar/wiki/Home/ :(

When you said "But in the description of the shield, it says this:" I was expecting to see a link to and a description of the hardware. Don't you have a link to the web page for the hardware you are thinking of buying?

One of the common problems with Open Source Software is poor documentation. My guess (and it is no more than that) is that the library needs access to the interrupts that are used by the regular Arduino HardwareSerial code (for example Serial.begin() ) and if you use the library you will not be able to use Serial.

Maybe someone else will come along who is familiar with the product. The chances of that would be much higher if you edit your Original Post and change the title to something more meaningful like "Help with XXXX shield" where XXXX is the name of the shield.

...R

Okay. I'm sorry for my unclear post! - I have edited my original post now. The link for the hardware can be seen in the post now.

If what you say is true about the library then I cant use multiple shields if I'm using this specific shield? Is that correct?

Nelly

Nelly: If what you say is true about the library then I cant use multiple shields if I'm using this specific shield? Is that correct?

The shield looks like it is intended for an Uno which has only one HardwareSerial port on pins 0 and 1. I don't know whether the shield will work on a Mega. The Mega has 3 spare HardwareSerial ports. I have no idea whether the use of the library affects them.

What do you want to use multiple shields for? I would always be wary of using multiple shields in case they conflict with each other.

...R

I want to communicate with my Arduino board from my PC wireless via BLE and therefore I need a BLE shield, and I want my Arduino to communicate with a LED driver using DMX/RDM.

Isn't a Arduino Mega capable of using the same shields as an Arduino Uno?

Nelly: Isn't a Arduino Mega capable of using the same shields as an Arduino Uno?

Some, but not all. For example the SPI pins on a Mega are not on 11, 12 and 13.

I assume the Bluetooth needs a serial connection. If you use a shield designed for an Uno you will be missing the opportunity to use the extra HardwareSerial ports on the Mega.

Life was not intended to be simple :)

...R

I wasn't aware of that :o Hmm.. There is nothing you can do about it, the shield is just designed that way?

Nelly: Hmm.. There is nothing you can do about it, the shield is just designed that way?

I don't know which shield you are talking about. But, to be honest, even if I did I would not have the answer. I have never used any shields.

...R

Okay. Thank you for all Robin2 - I really appreciate your help!