I am trying to connect both an SSD1306 module (from adafruit, https://www.adafruit.com/products/938 ) and a PJRC MicroSD adapter (https://www.pjrc.com/store/sd_adaptor.html)
When I connect just the microSD adapter to the teensy (using 11 - MOSI, 12 - MISO, 10- CS, 13, SCK) I can run the SdFat bench.ino test just fine.
It also runs fine when I connect most pins from the SSD1306 (except the SCK and DATA pin).
but when I connect the SCK teensy pin 13 to the SSD1306 SCK pin, bench.ino no longer succeeds. same when I connect the Data pin (to MOSI):
I hooked up my oscilloscope to the SCK pin to check out whats going on:
when the SCK pin is NOT connected to the SSD1306:
When the SCK pin IS connected to the SSD1306:
It seems that connecting the SCK pin to the SSD slows down the clock somehow. I have tried pulling CS on the SSD1306 to 3.3v in order to make sure its not trying to grab the SPI signal, but to no avail. Also I soldered the 3.3v jumper on the SD slot.
Anybody have any troubleshooting advice? I have a logic analyzer, which I will use next. Will post when I have more info.
Thanks!
T
When I connect just the microSD adapter to the teensy (using 11 - MOSI, 12 - MISO, 10- CS, 13, SCK) I can run the SdFat bench.ino test just fine.
It also runs fine when I connect most pins from the SSD1306 (except the SCK and DATA pin).
Code:
Use a freshly formatted SD for best performance.
Type any character to start
Free RAM: 58235
Type is FAT32
Card size: 31.91 GB (GB = 1E9 bytes)
Manufacturer ID: 0X3
OEM ID: SD
Product: SL32G
Version: 8.0
Serial number: 0X8D4E026
Manufacturing date: 6/2014
File size 1 MB
Buffer size 1022 bytes
Starting write test, please wait.
write speed and latency
speed,max,min,avg
KB/Sec,usec,usec,usec
277.64,112593,223,3671
Starting read test, please wait.
read speed and latency
speed,max,min,avg
KB/Sec,usec,usec,usec
1160.88,2220,431,879
1163.58,905,432,878
1162.23,905,431,878
1162.23,904,431,878
1163.58,905,431,878
Done
but when I connect the SCK teensy pin 13 to the SSD1306 SCK pin, bench.ino no longer succeeds. same when I connect the Data pin (to MOSI):
Code:
Type any character to start
Free RAM: 58235
Can't access SD card. Do not reformat.
No card, wrong chip select pin, or SPI problem?
SD errorCode: 0X1,0XFF
I hooked up my oscilloscope to the SCK pin to check out whats going on:
when the SCK pin is NOT connected to the SSD1306:
When the SCK pin IS connected to the SSD1306:
It seems that connecting the SCK pin to the SSD slows down the clock somehow. I have tried pulling CS on the SSD1306 to 3.3v in order to make sure its not trying to grab the SPI signal, but to no avail. Also I soldered the 3.3v jumper on the SD slot.
Anybody have any troubleshooting advice? I have a logic analyzer, which I will use next. Will post when I have more info.
Thanks!
T