Lolin ESP module
This little Chinese module is fantastic for those tight spaces where a full size module won't fit. There a selection of plugin boards for this little chap such as oled display, neopixel ring and lipo charger. surprisingly it has a usb uart bridge with buttons and transistors for rts dtr program mode. The board breaks out 8 Io pins RXD TXD and svn svp input ive used one of these in my inmoov's head to move eyes and jaw and in JD ,Hexi for neopixel lights build quality is good price is a little higher that others i paid around £8.00 from Banggood for my last few but also got some at half price wen they went on offer
4M flash 80Mhz
CH340 USB UART which runs at full speed
Runs at 240Mhz and doesn't get hot.
I give this board 9 out of 10 its a great little board for use where you haven't got much space like inside a bots head.
- Has a well thought out set of expansion boards
- Not a lot of IO.
- More expensive than others.
I purchased this module from Banggood as they were on sale at a really silly price of about £3 and as i was in the middle of doing my break out board i just added its footprint to the board. It is sold under the Geekcreit brand but a quick look at the back of the board shows that it is a doit.am board and unlike most of the other Chinese modules has a bit of support and documentation. There is a github source code page which has a port of their nodemcu luanode among other bit and pieces.
The board has a rev 0 silicon Wroom module with 4M DIO flash memory.
It has the CP2102 USB UART bridge and runs at 2Mbaud happily.
It has less pins taken out to the headers mainly the sdcard pins so is more compact than most other modules.
It has and LD11173v3 regulator and the RTS CTS transistor switching arrangement.
This a nice good quality module which is as good as the DEV-KIT C as long as you don't want to use the SD CARD pins. It performs as well as the DEV-KIT C and like the other Chinese board does not get warm even at full speed.
- Cheap even though it is not as cheap as when i brought it still selling at a little over £5.
- Small footprint.
- Fast USB UART Bridge.
- Rev 0 Silicon (although if you stick to the errata not really a problem).
I'm giving this board 9/10 really only because of the rev 0 silicon, Its a really good module Chinese module with documentation and source code to go with it and at a third of the price of the DEV-KIT C you can't far wrong and would recommended it if your on a budget or even if your not why pay 3 times more for a board unless you want the SD card pins.
I brought the Wrover from amazon at £49 as it looked like it had everything including a Jtag debugger , I have a Segger JLink Jtag which i had hooked to the Dev-Kit C with some small amount of success i could get it to see the device but when ever i tried to use a break point or step the code it all crashed horribly. I had high hopes seeing that Wrover had an integrated debugger so should work perfectly , couldn't have been more wrong got everything set up ocd driver built and gdb talking to it hook the board up Jtag found fine put in a break-point and debug. At this point i discovered a new windows 10 feature the Green screen of death ( see Microsoft listen to us all moaning about the blue screen of death) as much as the new feature was great to find it was really annoying as it proceeds to do its full memory dump and diagnostic check then reboot 10 minutes later your back up and running. After several green screens of death i decided that the debugger was a pile of poo and gave up messing around with it. My next step was get all the extras running lcd, camera , SD now comes the next problem source code? documentation ? it was only after spending hours scouring the web was i able to find documentation (this has recently appeared in the idf github page) then thankfully i found some code to get the display going as it is not documented which chipset the LCD is using then first bit of test code in and running for a while then green screen of death which i eventually solved by downgrading the ftdi drivers to use normal serial usb drivers which won't allow the Jtag run but at least i don't have to sit twiddling my thumbs staring a green screen.
4M flash, 4M PSram the ram is a nice addition but at a price you have to run the flash 40Mhz or it all goes pear shaped.
Dual port FTDI USB UART Bridge
- SD Card.
- 4M of ram.
- JTag this is a poor effort crashes all the time and not much use for anything other than backtrace.
- Poor Documentation.
- Poor Code support been forgotten in the idf.
This board gets a big thumbs down from me 2/10 for what on paper should be a cracking board but its badly supported and almost seems Espressif produced it and then lost interest as did i just to unreliable to be of any use, your better off getting a cheap module hooking a £5.00 spi lcd on and if you really need the extra ram over the 512k already in the device then stick an external one on your self and save yourself £30
Geekcreit / Geekwork easykit B1
After purchasing my Espressif Dev Kit C i saw this board on Banggoods site at just over £5.00 less than third of the cost of the dev kit c module so picked one up to see how it compared, I wasn't expecting much but when it arrived i was pleasantly surprised build quality was good with good amount of solder on the parts, the board layout is very similar to the dev kit C with a couple of noticeable differences which are easy to spot. Firstly it is red secondly it has a trapezoidal end under the esp32 Wroom antenna it also has a couple more gnd pins,annoyingly the pin layout is offset by one pin on the right side of the module so won't directly drop in to replace espressifs version with a couple of pins over hanging this is why my breakout has multiple connection options as it seems that every board made pretty much follows the guidelines on Espressifs site then moves a pin or two.
The Wroom module has 4M Dio spi flash fitted, and will run at 80Mhz with rev 0 silicon this gives me a bit of head scratching a small question when looking at rev number if you use various methods of reading the revision on various boards it is reported as R/W flash does that mean that its up to the end manufacturer to put the rev number in?
It has a ch340 usb uart bridge which gave me a few problems if i try to run faster than 115200Baud for some reason. My first module had a -B1 on the board now i've brought a few of these and they all had this problem of unreliability at faster baudrates, i recieved 3 more yesterday these are marked -C1 , these do not have the problem you can run the Uart at full speed.
it has the stock ld11173v3 regulator so gives you little bit of current for you to run your devices i put a 16bit neopixel ring on and it rand through its little routine without getting hot and i could light all at 33% before the temp starting creeping up.
Two switches labeled Reset and Flash, flash is connected IO0 to put it into program mode manually on the rev C1 board this has been renamed USER and IO0 also has an Led connected to it.
it has the usual two transistor arrangement on rts cts to put it into program mode via the usb for programming. The other change on the rev c board is the addition of a second led connected to IO27. I ran an extensive set of tests on this board and it did everything the dev kit C does except the comms on the -B1 board that has now been fixed on the C1- which isn't really surprising as it has the same WROOM module fitted.
now one notable difference with the devkit c is that runs cooler my devkit c gets warm where as this board does not.
- Runs as well as the Devkit C
- Unpredictables Comms on the rev -B1
- Larger than other modules.
- Lack of things to plug it into which led me to design the little breakout board (Gerbers available here)
i'll give it an 8/10 because of the comms problem its a nice board that works. Before i get lots of you saying another con is its got rev 0 silicon well we know all of rev 0 faults and there are work arounds, we dont know whats lurking in rev 1 yet, Mark my words it wont be to long before were all asking is it rev 2 silicon. i have done a lot of work on Arm and one of ST's chips is on rev R so imho better to know the bugs with a workaround than get bitten by another no ones seen yet
Being unfamiliar with Espressif micros i brought both of the development boards offered on Espressif web page and seemed a fairly good place to start the first to arrive was the DevKit C development board , good quality construction with two rows of pin headers which allow it to be plugged into bread board unfortunately that is about all it could be plugged into as i couldn't find any breakout board to fit it. I purchased the board from Amazon at a little over £15 the board comes equipped with a silicon labs CP2102 USB to UART bridge a couple of switches reset and the other to put it into program mode. The board has a LM11173v3 regulator to supply the power to the ESP32 module one thing i found with this board is that when running at 240Mhz the module gets quite warm and as you'll see in later reviews others don't, i can only assume that there's not much copper under the head pad on the bottom of the module. It has some transistor arrangement connected to rts cts which puts the device into program mode using the python script supplied by espressif in it's development framework ESP-IDF, never been sure what makes a framework different than an SDK.
The module fitted to the board has 4M of QIO flash which will run at 80Mhz REV 1 silicon. It has an LD11173v3 regulator or similar my old eyes struggled to read it but that's what the schematic said it was.
The CP2102 USB UART Bridge runs at higher programming speed 2MBaud
Two switches one connected to reset the other to IO0 so it can be manually put into program mode if required. It ran all the software thrown at it and even crashed on queue when i did something stupid like UN-initialised pointers.
- Rev 1 silicon so you can get away without reading the errata (for the moment).
- Fast USB - UART Bridge.
- Price it is quite a lot more expensive than many other boards on the market.
- Lack of things to plug it into which led me to design the little breakout board (Gerbers available here)
I've had hours of fun with this board and give it a 9/10 mainly as it is a lot more expensive that many other boards out there it would have been nice if Espressif had matched the foot print of their previous module the esp8266 but i suppose that's the price we pay to have more IO and faster devices any way i solved the problem by designing a little breakout board which only cost about $15.00 for 5 boards from Elecrow