Introduction: Super Chumby
The Chumby One, produced by Chumby Industries, is a great little radio with a great many features. Extensive alarm functions, many music sources, and customizable widget feeds leave any need satisfied.
To make up for the almost, I decided to try to fix the biggest gripe about the Chumby One so far, the terrible wifi reception. The chumby forums have countless threads complaining of the wimpy wifi adapter. Without a large pocketbook and intermediate linux skills to use a better wifi adapter, I had to improvise.
In addition I fixed my second biggest gripe, the battery life. The sub-amp hour battery that fits in the compartment allows for maybe an hour of battery life with music. Not good for the portable radio to carry around the house that i had hoped. So onto the hacking.
These modifications should get you an extra bar of connection on average and around 6 hours of battery life with internal speaker for about $40.
*Image of wifi adapter courtesy of iFixit
Step 1: Materials
Here is the break down for the Super Chumby
Chumby One- $79.95 (on sale)
2.1mm Power Jack CP-5-ND - $2.11
2.1mm Power Plug SC1052-ND - $3.44
RF Cable Assembly JF1R6-CR3-4I-ND $4.50
(2) U.L Receptacle H9161-ND - $2.88
Li-Ion 18650 3.7V 6600 mAh Rechargeable Battery module with PCB - $21.99
9dbi Wifi antenna - $6.99
(Any size/dbi rating would work, I just know this helped get a signal in my garage.)
All together the Super Chumby was the same as the Chumby One's normal price.
Tools/Supplies I used include:
Soldering Iron with fine solder - Preferably a point tip.
Panavice -Not mandatory, just really helps.
Flux Pen -Again not mandatory, just really help with SMD soldering.
Hand drill and drill bits. -5/16 and 1/4 if you use the same parts
Small Screwdriver - I really lucked out on this one. It just reaches the main chassis screws.
Step 2: Disassemble the Chumby
This process is pretty straight forward.
1. Remove white screw covers.
2. Unscrew back plate.
3. Remove back plate.
4. Remove Volume Wheel.
5. Unplug Microphone and LCD.
5. unscrew and remove acoustic chamber (big black plastic assembly).
6. Unscrew LCD plate and remove.
7. Unplug wifi adapter from USB board.
Anyone who has trouble with these steps can just follow ifixit's guide here. just don't take apart the inner chassis as it is not necessary. We want the bare body and wifi board separated to modify.
Step 3: Modify the Wifi Adapter
The wifi adapter has to be modified in order to add the U.FL connector.
First, the coupling capacitor to the antenna must be repositioned. Remove it by adding solder to each side and alternating heating each side until it comes off. Then solder the capacitor back on but rotated 90 degrees.
Second, place the connector with the signal pin (the copper strip on the bottom of the connector) touching the exposed pad of the capacitor but not touching any exposed copper on the board. Note where the ground tabs are and scrape away the silkscreen around where they will sit.
Finally, solder one tab down while holding the connector with the tweezers. Then the signal and ground pads. Be VERY careful to not get solder on the connector, it will interfere with the connector or even fill it in with solder. This is why the parts list calls for 2 connectors so to have a second chance. You will scream if you have to wait a week for a replacement to come it. Test the connection between the capacitor and center pin for continuity. If all is fine and dandy, move to the next step.
(Sorry for my sad attempt at macro photography. Taken with a point 'n shoot and the magnifier from my helping hands.)
Step 4: Make the Battery Jack
There are many reasons why I decided to remove functionality of the bottom battery compartment. First is the behavior of parallel resistors. The standard battery has a 10kohm thermistor reading the temperature in case the battery overheats. With no good 3 pin power adapter I just replaced it with a 10kohm resistor constantly connected. If someone was to plug in a standard battery with the 10kohm resistor in place, the resistance read by the chumby would drop to 5kohm and most likely trip the overheat sensor.
Second is that I have no plans to use the standard batteries ever again. Redirecting the power cable was easier than adding a new input line all together. Reuse the power wires and be done with it. If I was smart I would of kept the original board connector to ease future disassembly but this idea came about 30 seconds too late.
So onto construction. First, remove the small pcb from the bottom panel and desolder the wires. Slide an inch of heatshrink over the wires and then solder these wires to the new power jack. Black to ground/outside, red to center, and blue to a 10kohm resistor then to the same ground as black. Isolate each pin with a piece of electrical tape and heat the heatshrink to finish the connector.
Step 5: Add the Panel Mount Holes
Place the main body shell flat and dry fit the large black plastic assembly. From there find the best places to locate the power connector and RP-SMA connector. Mark with a pen and drill each hole. The RP-SMA connector has to take a 1/4 inch bit to fit and my power connector took a 5/16 inch. Clean the edges a little and test fit the connectors. If everything fits, move to the next step.
Step 6: Solder the Battery Pack
Now for quite possibly the easiest step.
Slide the plug cover over the wires.
Slide an inch of heatshrink over the wires.
Solder the red wire to the center pin.
Solder the black wire to the outside pin.
Slide the heatshrink in place and shrink.
Screw on the cover.
Get a drink, champ.
Step 7: Assemble the Super Chumby
Just follow the guide for disassembly in reverse and install the connectors. Make sure you tighten the nuts on the connectors else they will twist and possibly break wires. This is especially true for the RP-SMA connector. Don't break anything but make sure they are snug. Double check the U.FL connection and that the wifi adapter is plugged in fully. Then screw the back panel back on.
Step 8: Finishing Touches and Notes
For purely cosmetic reasons i then replaced the screw covers as this is a gift. Then take the Velcro and add a strip to both the battery and Super Chumby. Vertical is best as it allows you to place the bottom of the battery flush with the surface the Super Chumby is on. Else the weight can cause it to tip backwards. Finally attach the antenna and plug in the battery. Your Super Chumby is now finished! Plug it in, charge it, and enjoy around 6 hours of uninterrupted music!
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