Makerfocus 4pcs ESP8266 Esp-01 Serial Wireless Wifi Transceiver Module Compatible with Arduino

Super devices, work just fine. New to all this, but there is enough info out there and it got me going fairly quickly. I will be buying them again and again and again. If you plan to use the the SoftwareSerial library use a lower baud rate than 115600, this is a software serial bus emulator, so your hardware/software configuration may not be up to par. This is not a problem with the ESP8266, this little device works just fine. Another point worth mentioning is that if programming more than one Arduino through a Pi you will be using more than one instance of the Arduino IDE (one for each Arduino you are prototyping). For each instance of the IDE you need open it from the Rasperry Pi menu, don't open another sketch from the IDE menu.If you do the latter you will become unhinged trying to keep all the com ports and Serial monitors synchronised with each Adruino.

First I tried the ESP-01 flashing circuit that I used in the past and none of them would go to the AT command mode, I would see READY but could not go beyond that. I the tried using the Arduino UNO as the programmer. The terminal session came up as it should in the AT command mode and worked great. I then tried to flash the example blink program to it. It looked like it was working but when it was done the ESP module was not blinking and it would no longer process AT commands. Update 5/14. The seller immediately sent out 4 replacements. For some reason withe same flash setup they all worked. I don't know what the problem could have been but thanks to the sellers quick response every thing is good now.

I purchased some of these to attempt to roll my own smart switch. The boards seem decently constructed, but I really wish there was just a little bit more concise documentation out there SOMEWHERE. The Youtube links that Makerfocus provide seem to really emphasize the whole version 1 vs version 2 thing. I'm still not sure how that matters. The most useful page I found was the teomaragakis dot com blog post on "how-to-connect-an-esp8266-to-an-arduino-uno". Except it didn't work. I was able to use the Arduino IDE and an Arduino Uno to connect to the ESP board and use the Arduino IDE Serial Monitor to see the boot messages. I was also able to use GPIO00 to toggle between AT mode and Flash mode (neat tip I didn't see anywhere - the blue LED flashes twice on boot into AT mode, once on boot into flash mode). In AT mode I was even able to send it commands to connect it to my wi-fi. But every stinking time I booted into flash mode and attempted to upload a sketch, I would get the espcomm_sync errors that you find people complaining about all over the web. I tried all sorts of different settings in the Arduino Tools menu with no success but sometimes varying error messages. So I finally had success by... switching my board to an Arduino Mega. Some of the pages out there suggest the 3.3V supply on the Uno board is iffy. It seems that was my problem. When I switched out the board and used the Arduino Mega (with the reset held to ground), my sketch uploaded with no problem and immediately started running. My Arduino IDE settings are shown in the attached screenshot (choose your own port obviously)- hopefully this will help those that are just starting out. The Flash Size, Mode, and Frequency are all derived from the boot message in AT mode.

Let's be clear, this is not going to replace your computer, it's not a replacement for a lot of micro-controllers, but that doesn't render it useless at all. You will see many reviews telling you that there are only 2 GPIO pins. That's not quite true. The reality is that there are four physical GPIO pins on the connector, as both the rx and tx pins are usable as gpio pins, just as pins D0 and D1 on an Arduino Uno are usable. It presumes that you are not going to use them for serial IO, but if you are setting this device up to gather data from devices, and upload that data across a wifi connection to a server or to one of the various cloud services, you really don't need the rx/tx pins for console io anyway, and making use of them isn't a bad idea. As you go through the various sensors and output devices you will find that there are a lot of them that support or even only use i2c or iic. Pretty much any of those devices that have arduino support libraries can be used directly off of any of the gpio pins that are set up as sdc and sda. Probably the most frequent example of this is to chain together several i2c devices, a real time clock, a humidity/barometric pressure/temperature sensor, and an OLE display with i2c connectivity, and you've got a watch sized weather station. Or skip the Real Time Clock as you can get the time via ntp off of an even more accurate time source. Use a pcf8574 to turn those two i2c pins into 8 io pins, or better yet hang 8 of them off the i2c pins and get 64 i/o pins (digital) and continue to use the pressure temp humidity sensor at the same time. Oh, and you can use those 64 pins of i/o to drive a 16x16 array of LEDs, or use charliepixeling to control 4032 leds in a much larger display. Or put a 4x4 keypad on one pcf8574 and so on. The processor on the esp8266-01 can handle that load, though you may start to see throughput bottlenecks on the i2c bus. You can also mix busses, use i2c on the gpi0 gpi2 pins, and put a dht22 on the rx pin and a collection of Dallas OneWire devices on the tx pin. Yes there are limitations on this device. I don't recommend using it to try to build a web based oscilloscope, but even that is possible so long as you're not looking for high frequency capture. (At some level, looking at a chart graphing the change in temperature detected by a sensor is just that after all.) But it can easily be a part of many micro-controller projects, either as an interface providing WiFi, or as a stand alone micro-processor with some really outstanding characteristics.

I have 2 orders of this product. The first order all the 1MB chips work great; got me hungry for another order. The second order contained two 4MB cache units and two 1MB units. One of the 1MB has a bad efuse [bricked on arrived]. The two 4MB make up for the bad one 1MB i got i guess... Overall happy with the purchase given the price per unit. In both orders, the chips arrived in a single anti-static bag so not individually bagged as the product photo would suggest; ultimately not a concerning factor... would buy again - and will in the future. Thank you MakerFocus.

Doing small home improvement projects I did not realize what I was missing out until I discovered these. If you wanted to wirelessly control something, like an LED, you would normally buy a $20-30 smart plug and a power brick to plug into it, that would ultimately control your LED or motor. With this module you can put together a reliable and secure remotely controlled application in just hours. With Arduino studio and other free software out there you can quickly create all kinds of smart things and ultimately connect them to any home automation hub (I have Wink), Alexa, or anything else. Another huge advantage of these devices is that they do not require any specific manufacturer's cloud and app to operate - simply connect to your WiFi and do the job.

LATEST UPDATE: After messing with these for about 6 months, I've decided these are really not worth the effort. Makerfocus has been very good so far and working with me (sent a new set of chips during the messing around below) and all 4 have failed over the past 6months. Every time it's for a bad checksum error. The below info for flashing them is still valuable, but I don't recommend them at all due to the problems with bad memory chips. Ok, many reviews say contrasting things about these devices and there is a LOT of misinformation. First of all I LOVE THESE DEVICES!!! Now for the removal of misinformation (I have the older style chips): UPDATE: I think I know where the main problem others have had lies!!! The below was working great then everything just stopped working. Programmed and nothing. It didn't seem like anything was different. After 2 DAYS of messing around I found the problem. You MUST HAVE 10k resisters on RST, GPIO 0 and GPIO 2 to 3.3v. Once I discovered this from hours of Googling IT WAS LIKE MAGIC. Everything became stable, every flash worked. Flash mode QIO worked! (one suggestion was to use DOUT). I had problems with OTA and I realized that the default in Arduino for Flash Size is 512. I changed to 1M (No SPIFFS) and OTA update started working! ADDITIONAL INFO: I found that the blue led flickers if you don't add a 10k pullup resistor to the TX line if you aren't using it. #1 - These devices ARE flashable. I have no idea what people mean when they say that. #2 - You CAN use Arduino IDE and upload sketches. You just need a USB serial cable (see below for more info) and use generic esp8266 with the port of the usbserial and 115200 baud. Ok, now for the truth behind the misinformation: #1 - These devices can be troublesome to work with, but I don't think it's the device itself as the fact you have to communicate through serial. I spent an entire day getting to the bottom of the issues. - You must use a USB to Serial adapter to talk to them. - You have to tie the chip enable pin high and the GPIO0 to ground to program. You also have to remember to pull the ground after you flash to run the firmware. - The TX and RX pins are supposed to be 3.3v. I tried several cheap ways of converting TTL (5v) to 3.3v because I didn't want to be a $4 converter for a $4 chip and didn't have great results. I finally (and fearfully) just connected TX <-> RX and RX <-> TX and the chip came alive. I have flashed many times with no problems. The concern is damaging the RX on the ESP8266 but even on the official Arduino.cc website had a Fritz with the TX, RX hooked directly so I'm still not sure about it, but I'm taking my chances and once I'm done playing I'll not be flashing them that much anyway. If you have a USB to Serial that does 3.3v as well as TTL then no worries. UPDATE: I believe my USB to Serial is 3.3v AND 5v logic compatible so be careful on the above. - My USB to serial kept having problems and I'd have to unplug and replug every time I did a new flash. That might be the USB to serial. - I discovered using the esptool with --port /dev/cu.usbserial (I'm on a mac) --baud 115200 flash_id would tell me when I was talking ok to the chip. - The baud rate is 115200. - I used the python esptool and it worked fine. I even installed TASMOTA and ESP-LINK which are cool firmwares to play with. - Plan on powering the chip on and off with everything you do. Hard reset seems to leave the chip in lala as does adding and remove the gpio0 ground. I LOVE, LOVE, LOVE these devices now that I know how to work with them.

These make me weep with joy. With a minimum of effort, and a battery, these can serve up a website, or better still, send UDP data to other 8266s, or to a Mac running QLab software, allowing you to fire stage cues remotely, automatically. (You can have one read a switch so when a door opens, a sound effect plays, a stage light goes on, etc.) They are powerful enough to do a lot without being attached to any other microprocessor. Best of all, these arrive in just a couple of days, instead of weeks by ship! They'll change your life!