How does this dev board seem?

[technix]

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 buttons
• Connectivity: 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 I2S
• Camera: interface provided
• Storage: W25Q128 SPI Flash, microSD card
• Other: Light sensor, buzzer, 2x LEDs

[Ampera]

This is hand soldering? Pretty damn good.

It looks like a neat board with a bunch of cool features. Have fun with it.

[technix]

This is hand soldering? Pretty damn good.

It looks like a neat board with a bunch of cool features. Have fun with it.

Yes 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.

[chickenHeadKnob]

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 the www.openedv.com forum but found it tough going.

[iMo]

The defaults of FSMC is way to slow

Do 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.

[AndreZheng]

I thought you bought this board from openedv officiate website. So clean and well soldered!!

[technix]

I thought you bought this board from openedv officiate website. So clean and well soldered!!

I 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.

[dozimas]

Looking very clean and neat! Good job!
What are you using for hand soldering?

[technix]

Looking very clean and neat! Good job!
What are you using for hand soldering?

Atten 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.

[rcbuck]

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.

[technix]

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.

• Put 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