Back in January 2014 I announced the development if the CE644 development board v1.3. Things have been very busy since then, but I'm delighted to announce that the CE644 development board v1.3 is a fact!
Some features of the CE644 previous versions stayed, while others have been discarded. The most important change is the addition of the USB programming port! Here's a list of features of the CE644 v1.3
|CE644 v1.1||CE644 v1.2||CE344 v1.3|
|Battery for RTC chip||Yes||Yes||Yes|
|ISP programming header||Yes||Yes||Yes|
|USB programming port||No||No||Yes (FT232R)|
|2-Ch digital isolator||No||ADuM1200||No|
|4x20 LCD HD44780 compatible||Yes||Yes||Yes|
|4x20 OLED compatible*1||No||No||Yes|
|LCD contrast adjustment*2||Yes||Yes||Yes|
|LCD backlight control option*3||yes||Yes||Yes|
*1 Only tested with Newhaven NHD-0420DZW series of 20x4 character OLED*2, 3 Only used with a 20x4 LCD HD44780
I'm currently using one CE644 to control a ES9018 DAC and I'm planing to use another for controlling volume and inputs selection in my pre-amplifier. However, it's usage isn't restricted to control audio gear. It can be used in any case where a Arduino can be used.
Build it yourself
I won't be selling the CE644 v1.3, but who isn't afraid of some SMD soldering can build one themselves. All you need is a CE644 v1.3 PCB, a soldering iron and the components of course. Most of the SMD's are fairly easy to solder for a person with moderate soldering skills, but the FT232R chip can be a real challenge!
One or more CE644 v1.3 PCB's can be obtained by sending the gerber files to a PCB manufacturer. The needed components are listed in the bill of materials (BOM).
The gerber files are categorized as follows:
- Top layer: pcbname.GTL
- Bottom layer: pcbname.GBL
- Solder Stop Mask top: pcbname.GTS
- Solder Stop Mask Bottom: pcbname.GBS
- Silk Top: pcbname.GTO
- Silk Bottom: pcbname.GBO
- NC Drill: pcbname.TXT
- Outline layer: pcbname.GKO
Hint: On YouTube you can find lots of good SMD soldering instruction video's. Please do watch these first when you've never done SMD soldering!
Some building instructions
- Jumpers J1-J4 need to be installed when using a 20x4 LCD with HD44780 controller. They're needed to adjust the LCD's contrast and backlight brighness. They have to be left open when using a 20x4 OLED.
- The potentiometer is only for adjusting the LCD contrast, so it's is not needed when using a OLED.
- Transistor Q1 is used for controlling the LCD backlight. Leaf it out when using a OLED.
Please refer to the schematics below to see how all components need to be installed.
For normal use the CE644 v1.3 needs to be powered by an external 7-10V DC supply, which can deliver at least 500mA. The CE644 can not be powered over USB, so for serial communication the controller needs to be powered by a external power supply.
Another option is to use the 5V and GND header pins to power the controller. Make sure to apply exactly 5V. Higher voltages will destroy the microcontroller! At lower voltages the microcontroller becomes unstable when running at 16 MHz. Using the 5V and GND header pins to power the CE644 is therefore not advised.
External devices that need 3.3V or 5V can be powered from the 5V and 3.3V pin headers. Make sure that their total current draw does not exceed 500mA!
A note about the CE644 firmware
The CE644 Firmware I've written earlier to control a ES9018 DAC is not compatible with this version of the controller. There is a complete new firmware version being developed to control a ES9018 DAC. This version can be found at Github. At the moment of this writing the firmware is not finished and still contains some minor errors. The firmware is open source and published under the MIT Licence, so feel free to use, copy, modify, merge, publish or distribute the firmware.