How does this dev board seem? - Page 1
Forum section: electronics / general

author: technix
author_rank: Super Contributor
timestamp: March 01, 2018, 05:05:39 pm
content: This is one of those Chinese designed dev boards. I bought this as unpopulated PCB and hand soldered it myself.Main components:Microcontroller: STM32F417ZGT6. Store-bought ones uses STM32F407ZGT6, but I decided to step up to the one supporting crypto.Expansion RAM: IS62WV51216BLL-55TLI.Sensors: Invensense MPU6050, Aosong DHT12, capacitive touch panel, 4x user buttonsConnectivity: USB OTG, LAN8720A Ethernet PHY over RMII, 2x RS232, RS485, 1x USB serial, CAN, IR receiver, nRF24L01 module option.Display: supports various LCD modules.Audio: WM8978 codec over I2SCamera: interface providedStorage: W25Q128 SPI Flash, microSD cardOther: Light sensor, buzzer, 2x LEDs

author: Ampera
author_rank: Super Contributor
timestamp: March 01, 2018, 05:06:35 pm
content: This is hand soldering? Pretty damn good.It looks like a neat board with a bunch of cool features. Have fun with it.

author: technix
author_rank: Super Contributor
timestamp: March 01, 2018, 05:15:52 pm
content: Quote from: TwoOfFive on March 01, 2018, 05:06:35 pmYes I hand soldered this board. Actually I have two of those.I have no idea how to get the expansion memory up at its maximum speed though. The defaults of FSMC is way to slow - I need it operating at full 55ns. I even plan to get a 12ns SRAM chip for one of two boards down the road, which requires it to be up to speed even more.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: March 01, 2018, 09:46:39 pm
content: It looks good, however now that nxp i.MX RT1050/1020 are coming out I have switched interest to those. If a new board surfaces on taobao with one of these chips I hope you can give a heads up. I tried surfing thewww.openedv.comforum but found it tough going.

author: iMo
author_rank: Super Contributor
timestamp: March 01, 2018, 11:51:07 pm
content: QuoteDo not expect any miracles.. I did with F407 and 10ns sram (the fastest fsmc settings which worked reliably with 10ns sram) - when the external sram is used as the heap: ~3x slower, when you run the code off the external sram: ~8x slower than when run in the internal sram/flash.

author: AndreZheng
author_rank: Contributor
timestamp: March 02, 2018, 07:49:23 am
content: I thought you bought this board from openedv officiate website. So clean and well soldered!!

author: technix
author_rank: Super Contributor
timestamp: March 02, 2018, 10:50:36 am
content: Quote from: AndreZheng on March 02, 2018, 07:49:23 amI bought the board blank and soldered it myself. They don't offer any board with built-in crypto. My unit is based on STM32F417 which offers a crypto coprocessor. My intention for this board is to test microcontroller-level application of TLS 1.2.

author: dozimas
author_rank: Newbie
timestamp: March 03, 2018, 06:16:36 am
content: Looking very clean and neat! Good job!What are you using for hand soldering?

author: technix
author_rank: Super Contributor
timestamp: March 03, 2018, 01:23:46 pm
content: Quote from: dozimas on March 03, 2018, 06:16:36 amAtten 936 soldering station with no-name-brand chisel tip, Nippon Superior SN96CI lead-free rosin-core solder, no-name-brand flux (which I used a lot.) Basically a lot of el cheapos and some $30 solder.

author: rcbuck
author_rank: Frequent Contributor
timestamp: March 06, 2018, 12:06:06 am
content: How much trouble did you have soldering the LAN8720A Ethernet PHY and how did you accomplish that on such a small QFN package?I needed to assemble 10 boards about 6 months ago that had the LAN8720A on it. After looking at the size of the chip I decided it was beyond what I felt comfortable attempting. The part also has a heat sink pad on the bottom that I was concerned about. I thought about using solder paste and attempting it but finally just paid a Chinese house to assemble the boards.

author: technix
author_rank: Super Contributor
timestamp: March 06, 2018, 06:13:05 am
content: Quote from: rcbuck on March 06, 2018, 12:06:06 amPut a little bit of solder on the bottom pad.Hot air gun the LAN8720A on there. Press the chip down while hot to drive out excessive solder on the bottom.Solder the corner pins