I have been asked to update and upgrade an old scoreboard for a small rural town. They don’t have the money to buy a new board and the manufacturer’s wireless kit is not compatible with this board.
I want to try and use two XBee Pro S2B’s that I have to transmit and receive the existing comms between the controller and scoreboard, which is a small coax cable. I’ve been reading the user guide for these devices all morning and I’m not sure I’m any closer to knowing if this is possible. I saw mention of application transparent mode, which sounds promising, but I’m just not sure.
From what I’ve been able to gather, the signal seems to be some variant of a TTL serial signal and could have voltages as high as 24vdc so I know level shifting will be needed.
I’m looking for guidance and a nudge in the right direction.
I am reasonably sure the signal is 5VDC after seeing the 7805CT voltage regulator on the board. I think I understand how to use a level shifter to get the 5VDC signal down to 3.3VDC for the DIN. Does the same level shifting device shift up on the other end? Still working out the details on that.
Start with the basics. Take some photos and show what the current input mechanism of the board. Take a few photos of the buttons that you press to make the board work. You might be best to do an IO passthrough then.
Updating and upgrading the existing scoreboard is a practical approach given the budget constraints. Exploring compatible wireless options or finding cost-effective ways to improve the current board’s functionality could be a solution.
Having read through a few more examples and watched several YouTube video’s, I think I have my direction.
The signal is 5VDC. I think I need a level shifter, likely looking at the SparkFun XBee Explorer Regulated since it handles the shift as well as provides a convenient way to power the XBee and mount it in one package.
With both of the XBee’s in Transparent Mode, connect the out-going signal from the controller to the DIN of that XBee. In the scoreboard connect the DOUT to the receiving module.
bmwbykrydr - I would suggest using the XBee S2C modules with the 82.15.4 firmware installed or use the XBee PRO 900 HP for this application.
Using the Sparkfun regulated board is a good option to offer the 3V CMOS to 5V TTL level conversion. Just check with Sparkfun before you purchase it to ensure it will do what you want.
I suggest the XBee PRO 900 HP instead as it runs on the 900 MHz band. As long as this is in the U.S., that would be the preferred option. You will find that it will give you a better performance as it will not conflict with the other devices running in the 2.4 GHz bands. It also has a longer range.
Thank you Eric. I want/need to stick with the modules I have since they were no cost to me and therefor won’t cost the ball park anything either. The budget for this is not large at all. My range only needs to be around 300 feet so these should work fine. Interference shouldn’t be an issue either as the small town only has about 200 people and the field is not close to many of them at all.
Then make sure that you place the Coordinator on the sign side where it is mains powered. Also make sure you set the DL and DH values on both to the SL and SH of the other. I would also suggest making sure that you have a way to issue a Network Reset (ATNR0) on your router side.
