https://www.exploringrpi.com Companion Site for the book Exploring Raspberry Pi Fri, 27 Apr 2018 02:56:25 +0000 hourly 1 https://wordpress.org/?v=5.0.1 https://www.exploringrpi.com/chapter10/#comment-335 Sat, 17 Feb 2018 03:56:12 +0000 https://www.exploringrpi.com/?page_id=401#comment-335 @Craig: You might try playing with the “LH_THRESHOLD” constant in oledDHT.cpp. I was also getting checksum errors until I set that value to the high end of the range (38 in my case, running on a Pi 3 — this value seemed to work pretty good regardless of the CPU governor setting).

]]> https://www.exploringrpi.com/chapter10/#comment-333 Mon, 12 Feb 2018 06:21:34 +0000 https://www.exploringrpi.com/?page_id=401#comment-333 Note that the wiring diagram for the Adafruit 1.3″ OLED part is incorrect! The 3.3V power line from the Pi should be connected to the Vin line on the display, not the “3v3” line as shown here and in the book. (The Adafruit part has an on-board voltage regulator which generates 3.3V from the Vin supply, and the module’s “3v3” line is actually the regulated 3.3V *output*!)

]]> https://www.exploringrpi.com/chapter10/#comment-261 Sun, 30 Jul 2017 23:25:18 +0000 https://www.exploringrpi.com/?page_id=401#comment-261 In Chapter 10, I am trying to run chp10/oled/dht (sudo ./dht) which compiles from oledDHT.cpp using the Aosong AM2301 but I am getting all checksum errors (each byte = 255). However, when I run the dht program from chp06 without any wiring changes, it works without problems. I removed the display but still I get the same error. I get no compile errors. Any ideas???

]]>