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- 2Thanks; Do you think that I should rely on I2C to use multiple sensors?Sang Inn Woo– Sang Inn Woo2019-07-04 06:24:16 +00:00Commented Jul 4, 2019 at 6:24
- 1@Sang Inn Woo, Ah I guess you misunderstood my comments on I2C. I said I have bad experience using I2C bus and could not put more than 8 devices on the bus and performance is unstable. So I guessed DS18B20's 1-Wire bus should be as bad. However, I started testing from 1 sensor and adding one by by one. Surprisingly I can add 7 (I have only 7 on hand!) and found everything stable. So I guess there is hope to add to 60! I am using the python3-w1ThermSensor-1.0.5. and I found it easy to setup and test.tlfong01– tlfong012019-07-04 06:33:06 +00:00Commented Jul 4, 2019 at 6:33
- You might like to read my update, clarifying that I am NOT using I2C. I am still using 1-Wire bus. I can use any GPIO pin. I choose I2C Data pin because it has a built in strong pull up of 1k8. In other words, you can try any other pins. BTW, I don't follow your terminal commands listing 1-Wire devices. Please show me the link for those commands. Thanks.tlfong01– tlfong012019-07-04 06:44:53 +00:00Commented Jul 4, 2019 at 6:44
- 1@ tlfong01 Thank you very much for replying. I am just typing "cd /sys/bus/w1/devices" then "ls" to list DS18B20 sensors that I wired. Is my issue related to powering? In today's trial, when I used 5V 3A USB adapter, I can find four DS18B20 sensors per one bus. However, when I changed USB adapter with 5V 1A, I can find only two sensors. BTW, it would be grealty helpful if you can share details of wiring for DS18B20.Sang Inn Woo– Sang Inn Woo2019-07-05 13:02:24 +00:00Commented Jul 5, 2019 at 13:02
- 1Just as @tlfong01 did, I can now connect 10+ DS18B20 sensors to GPIO 2 or GPIO 3 (which are I2C buses) with stable reading. For GPIO 4, 17, 22, ..., I tried an 1k resister instead of 4.7k for pull-up following the recommendation from @Brick; then I can connect 10+ DS18B20 sensors to those buses. I believe that the problem is now solved with your help. I will try 60 sensors wired to a RPi in early next week and update the post.Sang Inn Woo– Sang Inn Woo2019-07-17 11:03:51 +00:00Commented Jul 17, 2019 at 11:03
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