I am going to use this forum post to collect my thought on building a robot shield for the TI LaunchPad. Comment and suggestions are much appreciated.
Rather than use the Arduino term 'shield', I'm going to try to coin a term and call adding a board to the LaunchPad "padding". So this is my Robot Pad for the LaunchPad. The Robot Pad will provide flexible options for powering motors, servos, sensors, etc.
The Robot Pad will provide three power options on the board. I discussed some options for power in this post.
- 3.3 V regulated power for the MSP430 processor and any 3.3 V sensors
- 5 V regulated power for running an on-board motor driver, and any servos or sensors.
- An unregulated Vin from battery or another source that will power the two regulators and can be used to power motors, servos, etc.
All 14 and 20 pin MSP430 processor I/O pins will be brought up to the pad. The I/O pins will be grouped into three banks. Bank1 will support 4 I/O pins for 14 and 20 pin processors. Bank2 will support 4 I/O pins for 14 and 20 pin processors. Bank3 will support 6 I/O pins for 20 pin processors.
Power for each bank will be selectable via a shunt jumper for either 5 V regulated or Vin unregulated power. In addition, the shunt jumper can be removed and 3.3V regulated power can be used via a jumper wire. This offers great flexibility for running a variety of I/O options.
- Bank2 will support an optional darlington array.
- Bank3 may also support an optional darlington array. (I haven't decided)
Through hole tie points will be provided on the processor side off all pins, before the IC sockets for the optional motor driver and darlington chips. This will allow you to bypass these chips and connect directly to the processor I/O.
A small prototyping area will be provided with through hole solder points. This will flexibility for connections on the Pad or to external boards.
Sounds great! I’ll buy one!
Sounds great! I’ll buy one!
Snort! I’ll have to finish
Snort! I’ll have to finish designing it first. Thanks for the vote of confidence.
Good to see that someone is
Good to see that someone is actually planning to use the LaunchPad and I’m looking forward to follow your progress.
With regards to the IO headers I think it would be useful if you added a row of GND and power so the user could use it to hook up servos. Ehh… I’m not even sure if the chip can handle servos?
Also if this is your first PCB you might take a look at some tips at Robot Room http://www.robotroom.com/PCB-Layout-Tips.html and maybe add “Wire loop for test probe hook”, as I find them very useful.
Ps. If you haven’t chosen the layout software yet I recommend DipTrace as users of LMR gets extra pins
Thanks for the advice. This
Thanks for the advice. This is my first PCB, so any suggestions are helpful. I also plan to review all the suggestions that Ro-Bot-X got when he planned out his Robot Shield for the Arduino (which I have ordered, btw).
I do plan for the I/O pins to have the row of power and ground, as you suggest. They will be in standard servo layout. My twist on it is to allow easy configuration on which of the available board voltages you connect to a particular bank of I/O pins.
I’ll check out those tips. I’ve been to that site before and it is a good one. I’ll consider wire loops or test points of some kind too.
I don’t understand your comments about extra pins for users of LMR, but I’ll look into DipTrace for sure.
The extra pins I’m talking
The extra pins I’m talking about is based on this post https://www.robotshop.com/letsmakerobots/node/6396
I got extra free pins from DipTrace with no questions asked. I just wrote them a mail and a link to my user.
Seconded, I got this deal as
Seconded, I got this deal as well and have enjoyed using the app.
Found this while randomly
Found this while randomly looking for info on the launchpad.
Nice find. I may order one
Nice find. I may order one for prototyping.