Changes between Version 3 and Version 4 of venice/thermal


Ignore:
Timestamp:
03/29/2022 05:12:58 PM (2 years ago)
Author:
Tim Harvey
Comment:

page clean-up and expand on reading board/cpu temperature

Legend:

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  • venice/thermal

    v3 v4  
    11[[PageOutline]]
    2 = Useful thermal Gateworks wiki pages =
    32
    4 * [/wiki/ventana/thermal_management Very Resourceful Thermal Management Page]
     3= See also
     4* [/wiki/ventana/thermal_management Ventana Thermal Page]
     5* [/wiki/newport/powerthermal Newport Thermal/Power Page]
    56* [/wiki/DVFS Dynamic Voltage and Frequency Scaling of the Processor]
    67* [/wiki/venice/power Venice Power Consumption]
    7 * [/wiki/faq#WhyarecertainareasontheboardwarmwithregardstotemperatureWhyismyboardhot FAQ - Why is my board running hot?]
    88* [https://shop.gateworks.com/index.php?route=product/category&path=70_72 Gateworks Shop - Heatsinks ]
    99
    10 = Thermal Ratings
     10= Venice Thermal
     11
     12== Venice Thermal Ratings
    1113
    1214Gateworks pre-installs a heatsink on the CPU for all Venice boards. This heatsink provides basic cooling for the board during development but customers need to design their own thermal solution based on their particular enclosure, environment and operating conditions.
    … …  
    2830
    2931=== CPU Temperature
    30 The IMX8MM internal CPU junction temperature can be read via Linux:
     32The IMX8MM has an interface for measuring the internal CPU junction temperature.
     33
     34A Linux {{{thermal sysfs}}} driver exists which supports reading the CPU temperature and configuring various limits.
     35
     36internal CPU junction temperature can be read via Linux:
    3137{{{#!bash
    32 cat /sys/class/thermal/thermal_zone0/temp
     38~# cat /sys/class/thermal/thermal_zone0/type
     39cpu-thermal
     40~# cat /sys/class/thermal/thermal_zone0/temp
     4159000
     42~# cat /sys/class/thermal/thermal_zone0/trip_point_0_type
     43passive
     44~# cat /sys/class/thermal/thermal_zone0/trip_point_0_temp
     4595000
     46~# cat /sys/class/thermal/thermal_zone0/trip_point_1_type
     47critical
     48~# cat /sys/class/thermal/thermal_zone0/trip_point_1_temp
     49105000
     50}}}
     51 * Linux {{{thermal sysfs}}} devices refer to temperature in milidegree Celcius thus 105000 is 105C
     52 * The above shows the {{{cpu-thermal}}} sensor currently measuring 59C with a 'passive' trip at 95C (at which point CPU frequency throttling will occur) and a 'critical' trip at 105C (at which point the CPU will reset)
     53
     54=== Board Temperature
     55Board temperature is monitored via the [wiki:gsc Gateworks System Controller (GSC)] via a thermister located on the board.
     56
     57A Linux {{{hwmon}}} driver exists which supports reading and configuring the MAX6642 in Linux:
     58{{{#!bash
     59~# DEV=$(for i in $(ls /sys/class/hwmon); do [ "gsc_hwmon" = $(cat /sys/class/hwmon/$i/name) ] && echo $i; done) # find GSC device
     60~# cat /sys/class/hwmon/$DEV/temp1_input
     6148100
     62}}}
     63 * Linux {{{hwmon}}} devices refer to temperature in milidegree Celcius thus 48100 is 48.1C
     64
     65The board temperature can also be shown in U-Boot:
     66{{{#!bash
     67u-boot=> gsc hwmon
     68temp    : 34.0C
     69vdd_bat : 0.000V
     70vdd_vin : 15.292V
     71vdd_adc1: 0.000V
     72vdd_adc2: 0.000V
     73vdd_dram: 1.101V
     74vdd_1p2 : 1.190V
     75vdd_1p0 : 0.976V
     76vdd_2p5 : 2.464V
     77vdd_3p3 : 3.226V
     78vdd_0p95: 0.939V
     79vdd_1p8 : 1.796V
     80vdd_gsc : 3.168V
    3381}}}
    3482
    35 The value show is C*1000 and the position of the thermal sensor varies per baseboard but is typically near the power supply.
    36 
    37 === Board Temperature
    38 
    39 The board temperature can be measured through the GSC:
    40 {{{#!bash
    41 cat /sys/class/hwmon/hwmon0/temp1_input
    42 }}}
    43 
    44 The value show is degress C*1000 and the position of the thermal sensor varies per baseboard but is typically near the power supply.
    45 
    46 = Venice Thermal Protection
     83== Venice Thermal Protection
    4784
    4885Thermal protection is offered by the GSC (Gateworks System Controller).
    49 Please read more on the [wiki:gsc#GSCThermalProtectionGSCv3firmwarev53 GSC Wiki Page]
     86Please read more on the [wiki:gsc#thermal-protection GSC Wiki Page]
    5087
    51 = Venice Heatsinks
     88== Venice Heatsinks
    5289
    5390The Venice System On Module (SoM) has a 20x20x10mm (LxWxH) aluminum heatsink for passive thermal dissipation.