by PaulL » Mon Jan 05, 2015 12:25 am
by PaulL
Mon Jan 05, 2015 12:25 am
For fun: To Brick (verb): to render as if to change into a brick; to render, for example, an electronic device, the technological functionality of a brick. Often used in the context of closed systems (embedded, mobile, etc) that cannot be easily repaired. "Bricking" a device can be permanent, or permanent in the sense that it is beyond one's resources / abilities to correct (ex, flash is fried, device is unrelentingly locked, board is physically damaged, etc).
About the glitchy behavior:
You mentioned a few interesting things there - the seperate "as a battery" power supply, the repackaged cells - I'd still put an oscilloscope on the power to see if there's a dip or noise in the power supply - can you get access to one at college? How many amps is the power supply rated for?
There are only a few things that can mess with serial communication: either end of the connections, or the something in the middle. Device-wise, the RN-1's serial hardware shouldn't be flaky (it could be, but I haven't seen it). The same should also be true PC-side, though an external USB to serial adapter could have its own issues if you're using one (some just don't work very well). If you're using one, I'd recommend trying a different make / model.
What may be more of the problem is the connection. If there is a grounding problem, you could see this kind of issue (if, for example, the ground on the power supply or the PC is different). I recommended same power strip for PC / modem issues when I did that kind of work a couple decades ago, same kind of thing here.
If the battery has the power (and from what you mention, it should - what was the Amp Hour rating of the cells?), then it is a communication issue. Still, I would remove the servo connections for testing, if only to reduce the chance that they're interfering with communications in any way.
The connection could also be bad on the small plugin jack at the RN-1, there aren't a lot of ways to fix this. There could be debris or a film on the contacts in the jack, contact cleaner may help, or may not do much - replacement is possible, if a similar jack can be found. Typically if you have a jack issue, it would work better if you put pressure on it from some direction. Could also be cold solder joints on the connector, or that the jack is still attached, but broken loose of its solder joints to where the connection isn't consistent (this should be visible under a magnifying glass, but I doubt that's the case here). An oscilloscope would be helpful as you could check the signals at the RN-1 (ex, make sure they aren't dropping out or are otherwise noisy). If the connection is physically good at both ends, a bad wire could be the issue, or there could be an electrical interference problem (ex, try a different location, different cable).
PC-wise, have you tried a different computer? If the serial port is native (built into the board and not a seperate USB to serial), there could be some problem with the port or with the OS (ex, IRQ conflict, though those should be a thing of the past). Could be port drivers, could be some other OS problem, easiest to try a different PC.
Of course, as a last, and perhaps most difficult means of testing, try another RN-1 board. In re-reading your post, you have a 2nd RN-1, so this leans back towards the PC and the cable (unless you've got two programming cables, then it's back on the PC or a grounding problem or noise issue).
For fun: To Brick (verb): to render as if to change into a brick; to render, for example, an electronic device, the technological functionality of a brick. Often used in the context of closed systems (embedded, mobile, etc) that cannot be easily repaired. "Bricking" a device can be permanent, or permanent in the sense that it is beyond one's resources / abilities to correct (ex, flash is fried, device is unrelentingly locked, board is physically damaged, etc).
About the glitchy behavior:
You mentioned a few interesting things there - the seperate "as a battery" power supply, the repackaged cells - I'd still put an oscilloscope on the power to see if there's a dip or noise in the power supply - can you get access to one at college? How many amps is the power supply rated for?
There are only a few things that can mess with serial communication: either end of the connections, or the something in the middle. Device-wise, the RN-1's serial hardware shouldn't be flaky (it could be, but I haven't seen it). The same should also be true PC-side, though an external USB to serial adapter could have its own issues if you're using one (some just don't work very well). If you're using one, I'd recommend trying a different make / model.
What may be more of the problem is the connection. If there is a grounding problem, you could see this kind of issue (if, for example, the ground on the power supply or the PC is different). I recommended same power strip for PC / modem issues when I did that kind of work a couple decades ago, same kind of thing here.
If the battery has the power (and from what you mention, it should - what was the Amp Hour rating of the cells?), then it is a communication issue. Still, I would remove the servo connections for testing, if only to reduce the chance that they're interfering with communications in any way.
The connection could also be bad on the small plugin jack at the RN-1, there aren't a lot of ways to fix this. There could be debris or a film on the contacts in the jack, contact cleaner may help, or may not do much - replacement is possible, if a similar jack can be found. Typically if you have a jack issue, it would work better if you put pressure on it from some direction. Could also be cold solder joints on the connector, or that the jack is still attached, but broken loose of its solder joints to where the connection isn't consistent (this should be visible under a magnifying glass, but I doubt that's the case here). An oscilloscope would be helpful as you could check the signals at the RN-1 (ex, make sure they aren't dropping out or are otherwise noisy). If the connection is physically good at both ends, a bad wire could be the issue, or there could be an electrical interference problem (ex, try a different location, different cable).
PC-wise, have you tried a different computer? If the serial port is native (built into the board and not a seperate USB to serial), there could be some problem with the port or with the OS (ex, IRQ conflict, though those should be a thing of the past). Could be port drivers, could be some other OS problem, easiest to try a different PC.
Of course, as a last, and perhaps most difficult means of testing, try another RN-1 board. In re-reading your post, you have a 2nd RN-1, so this leans back towards the PC and the cable (unless you've got two programming cables, then it's back on the PC or a grounding problem or noise issue).