 |
| PCA9555 demo board. GPIO pins are on the top. |
I will be using this to control a bank of relays from my Raspberry Pi. If you are not familiar with I2C on the RPI you might want to look at my posts about the PCA8591.
This time I bought the chip mounted to a board from ebay. I had to solder the header pins to the board so I could connect all the inputs & outputs.
jnewbigin@raspberrypi:~$ i2cdetect 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1.
I will probe address range 0x03-0x77.
Continue? [Y/n]
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: 20 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- -- As expected, the chip shows up at address 0x20. The PCA9555 is programmed by a set of registers. The registers are split up into ports or banks which operate on 8 bits at a time. The registers are:
- 0x00 Select Input values for bank 0
- 0x01 Select Input values for bank 1
- 0x02 Select Output values for bank 0
- 0x03 Select Output values for bank 1
- 0x04 Select Polarity Inversion for bank 0
- 0x05 Select Polarity Inversion for bank 1
- 0x06 Select IO Configuration for bank 0
(set/1 = input (default), clear/0 = output) - 0x07 Select IO Configuration for bank 1
(set/1 = input (default), clear/0 = output)
To read the first 8 inputs
i2cset -y 1 0x20 0x00
i2cget -y 1 0x20
To read the next 8 inputs
i2cset -y 1 0x20 0x01
i2cget -y 1 0x20 To set the first 8 bits to be outputs
i2cset -y 1 0x20 0x06 0x00
And to turn all the outputs on
i2cset -y 1 0x20 0x02 0xff
My next job is to hook up the relay boards but that requires setting up a more permanent power supply which can run the Raspberry Pi, drive the relays and power the relay devices. Hopefully photos to come soon.
how to control the pins by a c - code
ReplyDeleteHi. I have some sample code which I am almost ready to post. I got a bit distracted with hardware things but I am back on track now.
ReplyDeleteHello ,I'm working on this IC PCA9555 with esp8266 for i/o expander but I found one issue like one port as inputs and other one as output whereas in one input apply socket with switch
ReplyDeleteMy problem is when plug in and plug out from socket in that case pca9555 is reset again and again.
we are set the value of register through code but still have problem .
Please resolve my problem......
It is necessary to read more such messages. Tina
ReplyDeleteThanks for the helpful information you shared with us.
ReplyDeletescary maze game
Thanks for the valuable information and insights you have so provided here. bloxorz
ReplyDeletegoogle 1013
ReplyDeletegoogle 1014
google 1015
google 1016
google 1017
Indonesian single ladies are a delight to be around because of their positive natures and bubbly personalities. The typical Indonesian woman has tanned skin, dark hair, and even darker eyes. The modern Indonesian woman looks especially indonesian brides feminine with her petite body usually adorned with in fashionable wardrobe. She wears make up and her hair is usually carefully arranged. Perfect looks go along with a lovely character.
ReplyDeleteYou have a great blog here! would you like to make some invite posts on my blog?
ReplyDeleteBikepacking.quebect
Information
Click Here
Visit Web
I think this is among the most vital info for me. And i’m glad
ReplyDeletereading your article. But should remark on few general things, The
web site style is wonderful, the articles is really great.
온라인섯다
Hey, I just hopped over to your site via StumbleUpon. Not something
ReplyDeleteI would normally read, but I liked your thoughts none the less.
Thanks for making something worth reading.
안전놀이터
This comment has been removed by the author.
ReplyDeleteUse the i2cdetect command to scan for strands I2C devices connected to your Raspberry Pi.
ReplyDeleteThe PCA9555 is a 16-bit I/O expander that interfaces with the I2C bus. It allows you to extend fnaf game the number of GPIO pins available on your Raspberry Pi by providing an additional 16 configurable digital inputs/outputs. The configuration is done through a set of registers that control each 8-bit bank of I/O pins.
ReplyDeleteGames often encourage players Geometry Dash to experiment with different strategies and approaches, fostering innovation and creativity.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteA significant challenge in mapquest is figuring out the most efficient route. Players are rewarded for minimizing their travel time and distance by finding shortcuts or avoiding congested roads. High scores depend on how well you balance speed and accuracy.
ReplyDeleteI recently came across John's Linux Blog discussing the I2C 16-bit IO extender, and it’s a great resource for anyone diving into hardware projects! By the way, in between coding sessions, I like to relax with some casual poki games they're a nice break from all the tech stuff.
ReplyDeleteSprunki Looking forward to the next part with pictures when you finish connecting the relay and power supply!
ReplyDeletegeometry dash unblocked Lite is a great way to get a feel for the game without investing too much time. Anyone else tried the free version?
ReplyDeleteThe more you play slope unblocked, the more addicted you get. It’s a race to improve your score every time!
ReplyDeleteYour project using the PCA9555 I/O extender with the Raspberry Pi sounds MapQuest Route Planner exciting!
ReplyDeleteIncredibox Colorbox Mustard is incredibly addictive! I often find myself playing for hours, getting lost in the creative process. The thrill of crafting a new track and discovering unique melodies is unmatched. It’s a wonderful way to unwind while indulging my passion for music!
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThe Dino Game Offline is a built-in game in Google Chrome that activates when your device cannot connect to the internet. The player controls a small, pixelated dinosaur that runs through an endless desert landscape filled with cacti and flying birds.
ReplyDelete