hi this is an old thread but i just tried with devmem2 apparently i simply gets a value 0x20 that apparently mean the temperature sensor is off (TRM table 9-19)
i tried writing a zero byte (to turn it on/reset it) *devmem2 0x44e10448 b 0* but it seemed i continue to get 0x20 in return any 1 has similar response from BBB? devmem2 may need to be downloaded and compiled on the BBB itself: http://www.makelinux.net/books/embedded_linux_kernel_and_drivers/text152 On Sunday, December 1, 2013 at 1:00:56 AM UTC+8, Mark A. Yoder wrote: > > Indeed there is a temp sensor. I looked in up in the TRM and then wrote > this script to read it. > > *#!/bin/bash* > *# Reads internal temperature of AM335x* > *# 0x44e1_0000 is the starting address of the Control Module (Table 2.2 p > 171 of TRM)* > *# 0x0448 is the address of the bandgap_crtl register which has * > *# 8 bits (8-15) of temperature (Table 9-19 p 1137)* > *devmem2 0x44e10448 w* > *devmem2 0x44e10449 b* > *cat /sys/devices/ocp.2/44e10448.bandgap/temp1_input* > > /dev/mem opened. > Memory mapped at address 0xb6ff5000. > Read at address 0x44E10448 (0xb6ff5448): 0x0000301E > /dev/mem opened. > Memory mapped at address 0xb6f71000. > Read at address 0x44E10449 (0xb6f71449): 0x30 > 48000 > > I used devmem2 to read the register directly. The last command uses the > Linux interface to read it. I'm guessing the units are C, but the manual > doesn't say. > > --Mark > > On Friday, November 29, 2013 4:27:01 PM UTC-5, Gerald wrote: >> >> Technical Reference Manual. It can be found at the link I sent you. >> >> *"You can read about it in the TRM found >> at http://www.ti.com/product/am3359 <http://www.ti.com/product/am3359>"* >> >> It describes how the processor works and all the functions of the >> processor. It has all the addresses for all the internal components. Just >> do a search for Temperature sensor. >> >> Gerald >> >> >> On Fri, Nov 29, 2013 at 3:23 PM, Junkytomato <[email protected]> >> wrote: >> >>> Maybe I should have asked this originally… What does ‘TRM’ mean? >>> >>> >>> >>> *From:* [email protected] [mailto:[email protected]] *On >>> Behalf Of *Gerald Coley >>> *Sent:* Friday, November 29, 2013 1:12 PM >>> *To:* [email protected] >>> *Subject:* Re: [beagleboard] Temperature Sensor in my BBB >>> >>> >>> >>> I do not know how to access it. You can read the TRM and see if there is >>> a mechanism for accessing it and if so, what the address is. >>> >>> >>> >>> Gerald >>> >>> >>> >>> >>> >>> On Fri, Nov 29, 2013 at 3:01 PM, <[email protected]> wrote: >>> >>> It doesn't seem to be my finger heating it up; it hurts after half a >>> second or so, and I don't think that the human body temperature is enough >>> to hurt the human body, generally speaking ;). Anyway, do you know how I >>> can access it? I have a few packages that should be able to read built-in >>> temperature sensors, but none of them are able to locate it automatically >>> and I have no idea what to give it for 'Sensor location'. I don't see >>> anything mounted in /dev/ that could be helpful and I don't know enough >>> about Linux to know where else it could be. What is the 'location' that I >>> need to access it? >>> >>> >>> >>> On Friday, November 29, 2013 2:27:17 PM UTC, Gerald wrote: >>> >>> That is normal operation. When you hold your finger on it your skin >>> heats up making it hot The longer you hold it, the hotter it feels. >>> >>> >>> >>> The processor has on on-chip temperature sensor. You can read about it >>> in the TRM found at http://www.ti.com/product/am3359 >>> >>> >>> >>> Gerald >>> >>> >>> >>> On Fri, Nov 29, 2013 at 12:49 AM, <[email protected]> wrote: >>> >>> I was using my BBB recently and noticed that it gets pretty hot when it >>> runs for more than a few minutes (I've never really touched it while it's >>> on before). It doesn't seem to be a problem, but I was wondering if the BBB >>> had a built-in temperature sensor. I know some laptops have >>> internal thermometers, so does the BBB have one? It's meant as a minimal >>> device, so I would imagine it doesn't, but it would be nice to know if it >>> does! >>> >>> -- >>> 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/groups/opt_out. >>> >>> >>> >>> -- >>> 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/groups/opt_out. >>> >>> >>> >>> -- >>> 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/e4XDrG-9s68/unsubscribe. >>> To unsubscribe from this group and all its topics, send an email to >>> [email protected]. >>> >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >>> -- >>> 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/groups/opt_out. >>> >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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