**** BEGIN LOGGING AT Tue Nov 28 03:00:02 2017 Nov 28 03:00:29 I was wrong. It takes math. Dang! Nov 28 03:04:01 What bit ADC is on the BBB? Nov 28 03:05:06 Is out ADC bit on the SRM? Nov 28 03:06:20 http://lmgtfy.com/?q=beaglebone+adc+bit Nov 28 03:08:41 myself: What site is that? Nov 28 03:10:49 the best search engine for your query Nov 28 03:10:58 Oh. Thank you. Nov 28 03:11:14 Hey myself: What bit, 16? Nov 28 03:11:26 Come on, tell little, ole me. Nov 28 03:14:51 Forget it...I just found out that I need to check the Tech. Ref. Man. for the AM3359. Nov 28 03:15:00 Sorry to harass you. Nov 28 03:17:09 12 bit! Nov 28 03:17:17 Taw Daw! Nov 28 03:17:48 Sometimes, that old bbb still is amazing. Nov 28 03:18:24 12 bits... in theory anyway Nov 28 03:19:58 Oh...b/c 1.8v changes? Nov 28 03:25:59 iirc there's non-negligible noise, although it obviously depends on adc settings (sample rate, averaging) and source impedance Nov 28 03:26:58 For my testing, I am sure this will work out just fine. I have a "sen" moisture sensor from SparkFun. They even say that it will not last long (the sensor itself). Nov 28 03:35:51 If you were to shove several sensors into the same pot of soil, I'd be astonished if they agreed with more than 5 or 6 bits of precision anyway; soil moisture is not a precision quantity that's easy to finely measure. Nov 28 03:49:30 That is what I have found. I have to beware of voltage used also. So for instance, my 3.3v BBB is used instead of the 5v source. Nov 28 03:49:37 This makes a difference on my reads too. Nov 28 03:50:35 I found some math on working w/ ADC 12 bit modules/peripherals. Nov 28 03:50:37 ... Nov 28 03:50:59 I cannot get it to work just yet. My reads are 1, 1800, and 2234181. Nov 28 03:51:08 All of which mean nothing to me right now. Nov 28 03:51:51 I guess the sensor (three wire) only understands off and on/open and closed. Nov 28 03:52:00 ... Nov 28 03:53:00 From experience, three wire devices can read more back on the terminal. Nov 28 03:54:28 I mean... Nov 28 03:55:05 no moisture reads: 0, 0, 1091/moisture reads: 1, 1800, 2234181. Nov 28 03:56:18 I guess I will try to find a happy medium one day w/ this device. Nov 28 03:58:09 hi friends. Nov 28 03:59:07 Im facing compile errors with u-boot and linux-ti-staging build. Nov 28 04:01:44 CHK include/config/kernel.release Nov 28 04:01:44 GEN ./Makefile Nov 28 04:01:44 CHK include/generated/uapi/linux/version.h Nov 28 04:01:44 CHK include/generated/utsrelease.h Nov 28 04:01:44 Using /home/avi/Projects/BoardLabSetup/tmp/work-shared/beagleboard/kernel-source as source for kernel Nov 28 04:01:44 "4.4.91-gb9d9bc78b > /home/avi/Projects/BoardLabSetup/tmp/work/beagleboard-poky-linux-gnueabi/linux-ti-staging/4.4.91+gitAUTOINC+9d9bc78b62-r127a/build/.scmversion echo -gb9d9bc78b" exceeds 64 characters Nov 28 04:01:45 /home/avi/Projects/BoardLabSetup/tmp/work-shared/beagleboard/kernel-source/Makefile:1038: recipe for target 'include/generated/utsrelease.h' failed Nov 28 04:01:45 make[2]: *** [include/generated/utsrelease.h] Error 1 Nov 28 04:02:21 this is with the linux-ti-staging build. Nov 28 04:02:39 plz help me. Nov 28 04:07:54 "exceeds 64 characters" looks salient. Try moving it to a ocation with a shorter pathname and see if it fails the same way? Nov 28 04:10:33 sorry...this one is for the yocto group. Nov 28 04:17:58 myself: do you have experience w/ soil moisture sensors? Nov 28 04:32:19 I think this sparkfun thing/soil sensor can only distinguish b/t closed and open. Nov 28 06:03:27 set_: if you'd read the item description you'd know that this is not true Nov 28 06:05:23 set_: also, even if you buy the sparkfun item with ENIG, I'd recommend against powering it continuously. I've had very good results by switching on supply right before measurement and turning it off again after. Nov 28 09:18:08 tbr: I see that you are right. My software could be off a bit. Nov 28 09:20:06 tbr: Also, this is my first go around w/ the hardware. I will keep plugging at it. Oh and I read where it stated that I should not run a steady on w/ this hardware. Nov 28 09:20:07 ... Nov 28 09:20:27 the cheap chinese "soil moisture sensors" you can dissolve easily within a week or two by keeping voltage on. Nov 28 09:21:14 Oh... Nov 28 09:21:36 I guess I could use push button. Nov 28 09:21:41 https://plus.google.com/+ThomasRuecker/posts/N8amHVm8o5o Nov 28 09:23:17 tbr: I have been unable to get the sensor to read anything except for open and closed. Nov 28 09:24:47 I'd suggest to attach a volt meter to the output and simulate different moisture situations. Even putting fingers across the probe and pushing down can already show some result. Although the chinese parts use a different amplifier. Nov 28 09:25:04 Although I have no formal background w/ this type of three-pin device, I will learn more in time. Nov 28 09:25:06 ... Nov 28 09:25:32 I tried that "finger across" test and received no difference. Nov 28 09:26:10 I am using import Adafruit_BBIO.ADC as ADC to run this software. Nov 28 09:26:13 also make sure you're staying within the voltage range for the sensor. in case of a BBB that MUST ABSOLUTELY be below 1.2V or you might irreversibly damage the ADC Nov 28 09:26:33 Okay. Nov 28 09:27:08 err, 1.8V is the VDD_ADC Nov 28 09:27:12 I thought it was 1.8v... Nov 28 09:27:13 Yep. Nov 28 09:27:48 documentation is rather explicit that the ADC pins are 'never exceed' Nov 28 09:28:19 so make sure to power your probe from VDD_ADC or scale properly. The former being easier. Nov 28 09:28:36 Okay. Nov 28 09:29:13 Do you recommend any soil moisture sensors? Nov 28 09:30:16 depends™. If you can afford it, capacitive is probably the way to go. That's 20-30dB more expensive though. Nov 28 09:30:43 Oh. Nov 28 09:31:16 btw, the sparkfun sensor has a recommended VDD of 3.3-5V according to https://learn.sparkfun.com/tutorials/soil-moisture-sensor-hookup-guide Nov 28 09:31:36 Yep...I saw that. Nov 28 09:31:54 I see that have it working w/ the Arduino-like boards. Nov 28 09:32:43 well, incremental. Nov 28 09:33:12 Their software has a baud rate in it. Nov 28 09:33:35 I was unable to produce that aspect to the software so far w/ python. Nov 28 09:35:45 put your digital electronics aside and get to know the output characteristic using a multimeter Nov 28 09:35:59 I bet that will provide some insights Nov 28 09:36:06 Okay. I will try that idea. Nov 28 14:21:44 im trying to connect my beagle on mac book air, can you help? Nov 28 14:26:10 if the BBB is running up to date firmware, then it should just show up as network device, as far as I understand. Nov 28 15:59:10 Hi every body Nov 28 15:59:26 I amloocking for support with a compliance information Nov 28 15:59:35 ECCN of one of your products Nov 28 16:00:00 BB-BBLK-000 (CIRCUITCO) Nov 28 16:01:05 Lluvia: http://lmgtfy.com/?q=eccn+beaglebone+black Nov 28 19:55:28 hi there channel :-) Nov 28 19:57:37 anyone runs in pi 3 model B a sd-card bigger than 64gb? Nov 28 19:58:04 sorry in his/her beaglebone black Nov 28 21:21:28 hi Nov 28 21:22:02 I'm looking on a way to build a custom rootfs with de official linux kernel for the BB blue Nov 28 21:22:14 I use Buildroot to do this Nov 28 21:23:21 is there a board configuration available for the BB blue to build a bootable image with Buildroot Nov 28 21:23:22 ? Nov 28 22:21:27 Does anyone have experience with the Beaglebone blue? Nov 28 22:30:00 please ask your actual question Nov 28 23:23:02 Maybe that is the extent of their curiosity? Nov 28 23:38:03 Hi Guys, Does anyone know where is R168 on green beagle bone PCB layout please? Nov 28 23:39:14 The top overlay- reference designator are hidden in the gerbers files I found so far online.. Thank you for your help Nov 29 00:14:45 Hello! Nov 29 00:15:32 I'd appreciate it if I can get some directions to tackle the following problem: Nov 29 00:16:56 I need to interface directly to CAN transceiver and be able to read/write bits from/to the bus Nov 29 00:18:08 behind the transceiver, are you planning to use one of the CAN controllers onboard the am335x, or an external (spi-connected) controller? or roll your own in a PRU or something? Nov 29 00:19:57 The dcan sounds to be a convenient option. But I need to be able to do something before a frame's transmission is finished Nov 29 00:20:36 that sounds like really really tight timing requirements, i.e. using PRU would be your only option Nov 29 00:20:43 Ahh, you're trying to corrupt a frame on the wire and replace it with your own :) Nov 29 00:20:59 you got me :) Nov 29 00:21:29 I previously ran across an opinion from a PRU specialist who said the PRU doesn't have the resources to implement a full CAN controller, but if you look at what a real CAN controller does, there's quite a lot of edge-case handling that you could probably leave right out. Nov 29 00:22:29 I've spent like a week trying to figure out PRU and got lost. so I thought there maybe another way. From what you guys said, it seems to be my only option Nov 29 00:22:32 Here's the problem, though -- the sender of the legit message will know it got corrupted (that's inherent within CAN) and retry immediately, because it knows the arbitration process will grant it access to the bus if it has the lower ID. Nov 29 00:22:50 This isn't ethernet. :) It doesn't have a backoff timer.. Nov 29 00:23:53 So, if you slay that message every single time it appears on the bus, you'll both destroy the bus for anyone else (who has a higher ID and thus loses arbitration), and cause a fault when the sender's retry counter reaches its threshold. Nov 29 00:24:31 There are two approaches that actually work: Nov 29 00:24:31 but not if I do someing DURING arbitration phase Nov 29 00:24:51 If you do something during arbitration, you monopolize the bus and the message just retries a moment later. Nov 29 00:25:22 My goal is to target only certain IDs Nov 29 00:25:28 Anyway. A) let the "wrong" message go out, then the instant it's done, you follow it with the "right" one, and hope to replace it in the receive buffers of whoever you hope to fool. Nov 29 00:25:45 or B) get out the wire cutters and man-in-the-middle that shit. Nov 29 00:27:42 I like that. Could you elaborate on " edge-case handling that you could probably leave right out" please? Nov 29 00:27:57 sure, one sec. Nov 29 00:28:08 sure, thank Nov 29 00:28:13 thanks Nov 29 00:28:46 Error frames and overload frames, for one. They're in the spec but you can probably ignore them. Nov 29 00:29:52 Also I think for receiving, if you're only looking at the header, you can leave out all the CRC stuff and let the higher software layers handle that Nov 29 00:31:27 you might even be able to leave out the ACK mechanism, or you might find that particularly interesting and want to imbue it with special software hooks :) Nov 29 00:33:35 So just to make sure I get it, you're saying that I can modify the controller to only deal with the ID part and ignore the rest to do what I'm trying to achieve. Right? Nov 29 00:35:14 If you choose to implement a controller from scratch in the PRU to achieve the level of control you want, you'll find that the PRU probably lacks the resources to implement the whole spec, and to make it fit, you'll have to implement only the parts you care about. Nov 29 00:37:56 Thanks for that. Do I have options other than the PRU? Nov 29 00:40:48 Most existing CAN controllers on the market with these sorts of capabilities are FPGA-based, so there's that route. Nov 29 00:41:31 I did find some references to a CAN implementation that fits within the PRU of a DA8xx processor, but I'm not clear on whether those are beefier than the PRUs of an AM335x. Nov 29 00:41:52 (that was here: https://lwn.net/Articles/427905/ ) Nov 29 00:42:12 who knows, maybe it would work. I'm out of my depth there. Nov 29 00:43:12 I really appreciate your input myself and I'll check it out Nov 29 00:43:54 I really don't think it's gonna work the way you think it will; CAN is robust against the thing you're trying to do. But I'd love to be wrong. :) Nov 29 00:44:44 Suprisingly enough, I've seen people did it with Arduino Uno!! Nov 29 00:44:55 Ooo. Link? Nov 29 00:45:06 I've seen message replacement, but not overwriting. Nov 29 00:45:37 i.e. follow it quickly with the desired message and hope the receiver's buffer only has room for one, so the last one transmitted is sitting in the buffer when the software comes to check for it Nov 29 00:46:36 You can check it out here: https://www.politesi.polimi.it/bitstream/10589/126393/1/tesi_palanca.pdf Nov 29 00:50:15 Okay, that's what I mentioned in "cause a fault when the sender's retry counter reaches its threshold." Nov 29 00:50:55 you can kick that ECU off the bus, but it'll be unable to send any of its *other* messages either Nov 29 00:52:08 If a given ECU only sent one message, that would be fine, but in real networks, many ECUs are participating in many functions with different IDs Nov 29 00:53:04 If that's acceptable in your target architecture, then go for it, but it's not always the cleanest state to get a network into. Nov 29 00:56:25 I'm trying to cause the target ECU to retract because I'll be injecting a dominant bit that leads the target ECU to loose arbitration, not to cause a fault. Nov 29 00:56:58 I hope this is different from what you're saying Nov 29 00:58:00 it doesn't lose arbitration, it voluntarily stops talking because its error counter exceeds a threshold Nov 29 00:58:41 losing arbitration is a normal part of bus operation and it would simply retry once the bus returned to idle Nov 29 00:59:10 This is exactly my goal, to make it seem "normal" Nov 29 00:59:12 attacking it with error bits makes its error counter climb until it disables its transmitter Nov 29 00:59:45 and it knows about that, that counter within the controller is accessible to software Nov 29 01:01:24 losing arbitration won't keep the message from being on the bus, it'll simply transmit again as soon as the higher-priority frame is finished Nov 29 01:06:13 But isn't possible to keep losing as long as I repeat the injection? Nov 29 01:07:34 if it keeps losing arbitration, then you've DoS'd the bus for all frames of higher ID (lower priority) Nov 29 01:07:52 if it keeps getting transmit errors, then the error counter faults it out and it knows it's been messed with Nov 29 01:08:05 (it may not do anything with that knowledge, but it could.) Nov 29 01:08:21 I think errors are triggered out of the arbitration phase, right? Nov 29 01:09:42 it doesn't matter where the error occurs, it'll be counted in the error counter Nov 29 01:10:12 the only time it doesn't count as an error is during arbitration if it's just right and happens as a loss of arbitration, but that's not an error Nov 29 01:10:31 but because it's not an error, it'll simply retry the instant the bus is free again Nov 29 01:12:01 "myself", you're awesome and I really appreciate your time!! Nov 29 01:13:05 much obliged! I'm very curious what you come up with. :) Nov 29 01:13:20 pop into reddit /r/carhacking sometime Nov 29 01:13:55 Sure, will do. Have a great night :) Nov 29 02:17:15 Aha! Here's where they said it's not possible: https://e2e.ti.com/support/arm/sitara_arm/f/791/t/493750 Nov 29 02:17:57 Makes me even more curious about that DA8xx implementation Nov 29 02:26:22 da8xx (omap-L1xx) implementation? its pru subsystem is afaik considerably more limited compared to that of the am335x **** ENDING LOGGING AT Wed Nov 29 03:00:02 2017