HiLetgo PCF8574 PCF8574T IO Expansion Board I/O Expander I2C Evaluation Development Module (2pcs) Review

I bought these after reading some negative reviews about grounding the address pins on the board. I was hoping that the manufacturer would fix the issue after so many negative reviews but they didn't fix it. The boards I received also had some of the address pins grounded, so flipping an address jumper will result in a short between VCC and GND. This is an obvious oversight on the part of the manufacturer that can potentially cost you big bucks due to damaged parts. You must recall and replace…

The address pins (A0, A1 and A2) on BOTH the boards I received were grounded on the PCB. The top one is where VCC is and the next 2 columns were shorted on the PCB between ground and AO, ground and A1, and ground and A2. This prevents you from removing the bottom from the pin to pull it up. It also means that if you try to pull an address pin high, you're shorting VCC to ground. To change the address you will need to unsolder the address pins you wish to remove from the board.

If you need more I/O pins on your Arduino/ESP, look no further than here. This module gives you 8 digital pins without using any pins other than your I2C bus and power supply. I'm working on hooking mine up to an 8 relay module. Since I work with high voltage I have not posted any pictures yet. :) Pro tip: As others have said, the I2C address can be 0x38 or 0x20. If you have an I2C scanner sketch (and you should) it will take you a minute to figure it out. Do not worry. Change is part of life.

Update: The seller came forward to fix it and very apologetic about the initial problem so I'm changing my rating based on the good Customers have upgraded from 2 stars to 4 stars service. I ordered this two pack but one of them came without a square connector on the board. It's not damaged or broken, it doesn't exist at all! They just didn't solder the connector at the time of manufacture and put it in a pocket with no connector installed. The chips on the board were Philips A series (base…

The boards I received have version "A" of PCF8574. This means that the device address is different. If your code uses 0x20 as the base address, you need to change it. It took me some time to figure that out. EDIT: HiLetgo contacted me after I posted a three star review and offered a partial refund which I accepted. I am updating my rating to four stars based on their customer service and the fact that the boards worked great after I discovered the difference in part numbers and started using…

Update: The seller got in touch to fix the issue and are very apologetic about the initial issue so I'm downgrading my rating to 2 due to the good quality Raised customer service to 4 stars. I ordered this two pack but one of them came without a square connector on the board. It's not damaged or broken, it doesn't exist at all! They just didn't solder the connector at the time of manufacture and put it in a pocket with no connector installed. The chips on the board were Philips A series (base…

GPIO pins are generally in short supply on most microcontrollers. These boards are a great way to add some 8-bit I/O ports to your device. I had a base address of 0x20, apparently some have a base address of 0x38. If in doubt, the code for the I2C scanner is easy to find. You can also just try 0x20 and if that doesn't work try 0x38. These devices can be easily cascaded, one device can be connected to a second (or third or fourth) up to eight. Of course you need to install address jumpers so…

I bought these after reading some bad reviews about grounding the address pins on the board. I was hoping that the manufacturer would fix the issue after so many negative reviews but they didn't fix it. The boards I received also had some of the address pins grounded, so flipping an address jumper will result in a short between VCC and GND. This is an obvious oversight by the manufacturer that could potentially cost you big bucks due to damaged parts. You must recall and replace all inventory…

The address contacts of these boards are permanently connected to ground in the address switch circuit. Attempting to select anything other than ground for the address pins will result in a short circuit to ground. Luckily the trace that does this is present on the back and if you cut with a string knife like in the picture full functionality is restored in 30 seconds of work. Note: Only cut between the jumper pins as shown in the picture, I scratched a bit higher but didn't cut these traces…