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Asked — Edited
Resolved Resolved by ptp!

Serial Communication To Vintage Rs-232 Device

Hello All,

I am attempting to communicate to my Heathkit Hero Jr. using the Terminal EZB control. I have no trouble communicating with it via TerraTerm/Hyper Terminal. I have connected the TX on the robot to the RX line on UART #0 and the RX on the robot to the TX line on UART #0 and the ground to the ground on UART #0. The robot is using 5V logic, so I purchased a 2 way logic level shifter as well.

The Hero Jr. robot communicates at 9600 baud, has 7bit data, even parity, and 1 stop bit, and no flow control. I didn't see anywhere to set these parameters (except baud) in the Terminal EZB control. When I do connect the robot and initiate the baud rate, I get a constant stream of "?" characters in the terminal window. Does anyone have any advice for how to get things talking?

Many thanks!


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I checked also the SDK and i didn't find a way to change from 8-N-1 to 7-E-1.

I believe you will need to interface a micro-controller between EZ-B and the Heathkit Hero Jr.
That's too bad - the ez-b does use the 8n1 standard. The only solution is to implement an arduino or similar micro in between as a translator.
Thanks, guys. No problem, DJ! The Ez-b already does far more than I would have imagined. Fantastic little product!

I've ordered a Max232 chip to interface between the Hero Jr and an arduino. I will post the results once I get him chatting happily.
Have I mentioned how jealous I am of your hero:D
*me 2

Max232 solves part of the problem: Rs232 <-> TTL/cmos.
After that, let me know if you need help with the micro-controller to convert from 8-n-1 to 7-e-1.
@ptp, Thanks! I was poking around online and found a software serial library(github.com/ledongthuc/CustomSoftwareSerial) that allows for different serial settings. I will give that a shot, but if it doesn't do the trick, I may indeed reach out! I am pretty excited to get the EZB talking to the Hero Jr.

@DJ Sures, Haha, I've had that Hero robot since I was 6 years old. In fact, there is a little sticker on the back that my father filled out when he assembled the kit that says, Dec 24th 1986. So Hero's 30th birthday is coming up quickly!