Arduino Shield Compatability on Arty S7

[rob2018t]

Dear Forum Colleagues,

I have a Digilent Arty S7 board and would like to integrate an Arduino shield that I own but am cautious as the Arty user manual states "Note: The Arty S7 is not compatible with shields that output 5V digital or analog signals. Driving pins on the Arty S7 shield connector above 5V may cause damage to the FPGA.". The shield I bought is the Velleman LCD Keypad and the instruction pdf is here

Has anyone used something like this before and can provide some advice? I assume the Arduino shield is 5v but the sentence above seems to contradict itself. The shield does mount to the Arty S7 properly (but I haven't powered it up).

regards

Rod

 

 

[JColvin]

Hi @rodb2018,

I'm not certain if you can use that particular shield or not; I looked at all the documentation that I could find on their website here, but I can not find anything definitive stating if the entire board uses 5V logic or if there is a level shifter elsewhere on the board, leading me to suspect that it is expecting 5V logic based on the datasheet for the display itself.

I'm not sure what you mean by the "above sentence seems contradictory". The FPGA pins that are routed to the pins on the shield connector are not designed to support 5V logic, so if 5V logic is applied to them, there is a chance you will burn out that particular pin on the FPGA so that it is no longer usable.

Let me know if you have any other questions.

Thank you,
JColvin

[rob2018t]

Thank you taking the time to look into this and explaining it further for me.

I thought the sentence was a bit odd as it said it isn't compatible with 5v and then stated that pins should not be taken above 5v...which implies 5v is OK afterall. However your sentence is much clearer and I understand it now - "the FPGA pins are not designed to support 5v logic"

Thanks for your help.

Rod