No, [email protected] Gerald
On Tue, Jul 21, 2015 at 11:48 AM, Alan Rosenbloom <[email protected]> wrote: > OK - great!. For a direct email, is your address [email protected]? > > Alan > > On Mon, Jul 20, 2015 at 9:57 PM, Gerald Coley <[email protected]> > wrote: > >> That is a long email. Send me a direct email, and at some point we can >> have a discussion. >> >> Gerald >> >> >> On Mon, Jul 20, 2015 at 6:36 PM, Alan Rosenbloom <[email protected]> >> wrote: >> >>> Gerald: I am super impressed that you would offer your valuable time to >>> help with not much in return than thanks. >>> >>> Background: I’m developing a complicated prototype and I am new to >>> embedded systems. I was fairly frustrated that I could not “just hook >>> things up” and have them at least not destroy the BBB while testing. I am >>> beginning to understand that, like any device, more capability comes with >>> more complexity and vulnerabilities. I still see the BBB as an amazing >>> opportunity for inventors overall and realize that I need to learn more to >>> use it properly. >>> >>> I cannot point to one circuit that caused the damage to >>> the BBBs because I am trying different arrangements to integrate multiple >>> devices. However, if you could answer some basic questions on design >>> strategy, that could help. >>> >>> >>> *Here’s what I need to accomplish:* >>> >>> I need to power 4 accessories: (1) a small stepper motor through the >>> Pololu DRV8834 driver board. It consumes about 200 – 300 mA at 5 volts, (2) >>> an IC chip via pulse wave modulation – it requires about 620mA at 1.55V, >>> (3) a small DC motor which consumes about 40 mA at 3V (either by PWM and >>> a relay or straight from a 3.3 V source) and (4) a small cooling fan – >>> consumes about 120 mA at 5 V. >>> >>> I need to control turning all these on and off by a clock function. >>> >>> I need to read a GVS digital sensor: consumes less than 10 mA at 5 V. >>> >>> I need to read a GVS analog input: 5V input, output < 1 volt. >>> >>> I need to read DC voltages (analog): (1) on a pin on the DRV8834 driver >>> board (0-1 volt range), (2) on a sensor with special input requirements – >>> it needs both (+) 5 volts AND (-) 5 volts inputs to power it. The (-) >>> voltage is derived from (+) 5 V using this inverter ICL7660A, which I have >>> found to be about 91% efficient at converting DC (+) to DC(-) for this >>> application. Sensor output max about 1.2 volts. >>> >>> Finally, I need to add and read a real time clock (RTC) such as the >>> Chronodot (Adafruit) – requires I2C bus SDA, and SCL, as well as GND and >>> (+) 5V. >>> >>> >>> *What do you think of these strategies:* >>> >>> (1) Use the BBB-GVS board (http://beagleboard.org/project/BBB-GVS/). >>> This board appears to provide a layer of protection from the sensor voltage >>> inputs and power outputs for the BBB. The problem is they may not be a >>> reliable supplier and I cannot tell if this board will accomplish all these >>> tasks. >>> >>> (2) Use the BBB only for logic and supply all the power from an >>> independent (probably 5V cell phone charger power pack) source with voltage >>> regulator, using PWM and relays to regulate the voltages lower than 5 V and >>> relays to control intermittent power needs. Would this be safer for the BBB >>> i.e. not using power directly off the BBB while trying to read sensor >>> output at the same time? It seems dangerous to me tying all the grounds >>> together (analog, digital and power) that would be required to get both >>> power out of the BBB and signal into it. >>> >>> (3) Power the BBB via a 3.7 volt backup battery through TP5 and TP8 >>> to prevent abrupt cessation of power should a system failure occur. Seems >>> like it would be possible to write code to give the “sudo shutdown –h now” >>> command when the power went down. This would allow the PMIC time to do an >>> orderly shutdown. >>> >>> >>> >>> I suspect that the sensors may be putting voltages on the BBB pins >>> before they are powered up as part of the problem, but I am not sure how to >>> prevent this. Is there a way to power up the sensors after the BBB has >>> properly booted and to shut them down before the PMIC does its shutdown >>> sequence? Any other external wiring or devices that could help safeguard >>> the BBB? Any advice you can offer on any of this or other ways to protect >>> the BBB would be appreciated. >>> >>> On Sat, Jul 18, 2015 at 8:31 PM, Gerald Coley <[email protected]> >>> wrote: >>> >>>> If you do not use it properly, it will be damaged. That applies to >>>> every electronic circuit ever designed. I would have stopped using the >>>> circuitry after the second try. >>>> >>>> I would be happy to look at your circuit and see if I can identify what >>>> the issue might be. >>>> >>>> Gerald >>>> >>>> >>>> On Fri, Jul 17, 2015 at 10:27 PM, <[email protected]> wrote: >>>> >>>>> I now have 4 damaged or dead BBBs. On this last board (Element 14), I >>>>> had only a stepper motor driver board connected (Pololu DRV8834), and >>>>> nothing else. The DRV8834 was initially drawing power from the VDD5v on >>>>> the >>>>> BBB. The BBB "blacked out" twice while nothing was happening and while >>>>> connected to both a 5V regulated power supply (Adafruit) and USB power. I >>>>> was worried that the DRV8834 was drawing too much power (although I have >>>>> found it uses < 200 mA @ 5V), so I used a separate power supply for the >>>>> DRB8834. Only the logic of the DRV8834 was hooked up to the BBB - nothing >>>>> that would supply power and no analog inputs. The third blackout also >>>>> occurred without an obvious precipitant - again with both power sources >>>>> connected (USB and barrel plug). Now the power LED flashes briefly when >>>>> either USB or barrel plug power (Adafruit power source for BBB) is >>>>> connected to the BBB. It will not sustain the power button nor boot up. >>>>> >>>>> This seems to be a repetitive theme on this forum. I am losing faith >>>>> in the BBB ever functioning in a real world environment if it is this >>>>> fragile. Is there any way to protect the BBB processor (or whatever is >>>>> blowing) with external circuitry or power? >>>>> >>>>> Appreciate any help. I'm now out over $200 with these boards and I >>>>> cannot identify anything that should be damaging them. Considering >>>>> changing >>>>> to another system at this point. Although I am impressed with the >>>>> capability of the BBB, I would not call it a robust system. >>>>> >>>>> Help! >>>>> >>>>> >>>>> >>>>> On Thursday, June 11, 2015 at 9:08:39 PM UTC-4, Gerald wrote: >>>>>> >>>>>> The flashing LED indicates excess current is being drawn by the >>>>>> processor. This can be related to damaged I/O pins or power supplies that >>>>>> are not well regulated.. >>>>>> >>>>>> Gerald >>>>>> >>>>>> >>>>>> On Thu, Jun 11, 2015 at 4:38 PM, <[email protected]> wrote: >>>>>> >>>>>>> I have the same issue, already 3 boards has died. >>>>>>> any solution, i tried to use optoisolator/pwm and noting. the BBB is >>>>>>> a bad board. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Le mercredi 25 février 2015 18:03:24 UTC+1, [email protected] a >>>>>>> écrit : >>>>>>>> >>>>>>>> Identical problem this morning: BBB boots fine when powered by >>>>>>>> USB, but not when powered by a 2.0 mA rated 5.0 V DC power supply >>>>>>>> (nicked >>>>>>>> from some other device). BBB power LED blinks continuously. This >>>>>>>> power >>>>>>>> supply has worked with this BBB in the past. >>>>>>>> >>>>>>>> Mike. >>>>>>>> >>>>>>>> On Friday, January 23, 2015 at 8:44:59 PM UTC-8, [email protected] >>>>>>>> wrote: >>>>>>>>> >>>>>>>>> I had a similar problem- my power LED would just continue blinking >>>>>>>>> when connected to a 5V power source. This meant there was something >>>>>>>>> wrong. >>>>>>>>> First, I checked if my BBB was still alive. To find that, I connected >>>>>>>>> my >>>>>>>>> board to a computer via USB. Surprisingly, this time power LED >>>>>>>>> turned on >>>>>>>>> normally. Then to make sure that everything was properly, I ran some >>>>>>>>> program as given in the BB website >>>>>>>>> http://beagleboard.org/getting-started. I was happy to see, the >>>>>>>>> programs on the website worked just fine on my board. Thus, I was >>>>>>>>> able to >>>>>>>>> conclude that strangely, my BBB board didn't like 5V external power >>>>>>>>> source! >>>>>>>>> >>>>>>>>> On Friday, November 22, 2013 at 6:41:41 AM UTC-8, Bert Lindner >>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Just had a 5V powered Beaglebone Black seemingly die on me. First >>>>>>>>>> the power led kept blinking, then after removing the (BB Toys CAN) >>>>>>>>>> cape the >>>>>>>>>> power led would flash just once after applying power. Looking back in >>>>>>>>>> previous threads this seemed to mean I killed the board somehow; >>>>>>>>>> there was >>>>>>>>>> also a GPS module attached to one of the UARTs and a probably power >>>>>>>>>> hungry >>>>>>>>>> USB wlan stick that I'm trying to get to work, so a power hungry >>>>>>>>>> setup. >>>>>>>>>> >>>>>>>>>> I was ready to declare it dead, it remained just flashing once >>>>>>>>>> after repeatedly unplugging and reattaching the power supply. >>>>>>>>>> >>>>>>>>>> However I noticed the single power led flash would also happen if >>>>>>>>>> I pressed the power button (leaving the 5V plug in). Doing that >>>>>>>>>> repeatedly >>>>>>>>>> seems to have revived the board, will see if new problems occur. For >>>>>>>>>> now it >>>>>>>>>> behaves normally. >>>>>>>>>> >>>>>>>>>> Is this expected behaviour? >>>>>>>>>> >>>>>>>>>> Best, >>>>>>>>>> >>>>>>>>>> -Bert >>>>>>>>>> >>>>>>>>>> -- >>>>>>> For more options, visit http://beagleboard.org/discuss >>>>>>> --- >>>>>>> You received this message because you are subscribed to the Google >>>>>>> Groups "BeagleBoard" group. >>>>>>> To unsubscribe from this group and stop receiving emails from it, >>>>>>> send an email to [email protected]. >>>>>>> For more options, visit https://groups.google.com/d/optout. >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Gerald >>>>>> >>>>>> [email protected] >>>>>> http://beagleboard.org/ >>>>>> >>>>> -- >>>>> For more options, visit http://beagleboard.org/discuss >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "BeagleBoard" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to [email protected]. >>>>> For more options, visit https://groups.google.com/d/optout. >>>>> >>>> >>>> >>>> >>>> -- >>>> Gerald >>>> >>>> [email protected] >>>> http://beagleboard.org/ >>>> >>>> -- >>>> For more options, visit http://beagleboard.org/discuss >>>> --- >>>> You received this message because you are subscribed to a topic in the >>>> Google Groups "BeagleBoard" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/beagleboard/jBFshjlPeHI/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> >> >> -- >> Gerald >> >> [email protected] >> http://beagleboard.org/ >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/jBFshjlPeHI/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- Gerald [email protected] http://beagleboard.org/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
