A Panelolu is an SD-card reader/LCD display/rotary encoder controller for Sanguinololu based 3D printers such as the Solidoodle. It allows various functions to be controlled from the Panelolu as well as the usual computer based software. It also allows printing from a micro SD card, which means a computer is not actually needed to run the printer if the user desires.
 Step 0: Prepare
Check for all components:
- 1x Ribbon cable
- 1x 10pin connector
- 1x 24pin connector
- 3x 6pin connectors
- 1x 2 pin connector
- 5x 6pin header
- 1x 2pin header
- 1x PCB with LCD panel
- 1x SDSL sd card reader PCB
- 1x bag of screws, nuts, bolts
- 1x bag crimp connectors (~22)
- 1x presoldered PCB with rotary encoder, reset switch and trim pots (option)
- 1x 1284P microcontroller with bootloader already installed (option)
- Soldering iron and solder
- Wire stripper
- Solder sucker/solder braid
- Curved needle nose pliers/ribbon cable pin crimping tool
- Masking tape and a pen
- Heat shrink and a lighter (optional)
- Small vice
A modified schematic has been created with shows the wiring requirements much more clearly.
 Step 1: Narrow the Ribbon Cable
Count pins on ribbon cable. If you were supplied with a 24pin cable, split and remove two pins from the non-red side to make it a 22pin cable. Keep the leftover wires for later.
 Step 2: Solder LCD PCB headers
Solder on two of the 6pin headers to the large PCB. They should be at either end leaving 4 holes in the middle. Facing them as shown will make the installation neater later on.
 Step 3: Add SDSL 10pin connector
Counting from red side as pin1, locate pins 13-22. They should be the 10 pins furthest away. Split and separate about 10cm (4 inches). At this stage it’s a good idea to get some tape and start labeling everything.
Locate the grey 10pin connector and orient it as shown the on the original instructions:
Press the large end of the grey connector against pins 13-22, where you will see the sharp metal teeth ready to penetrate the rubber insulation. When in position, use a small vice to evenly apply pressure until the small grey cap has clipped into place. Note the position of the connector along the ribbon cable.
 Step 5: Separate and Label Wires
Time to separate all of the wires ready for the fun part. Have tape ready to label each as you go. Start by splitting away pins 1(red stripe) and 2. These supply 12V and will not be used in this installation, but now are wired in for something else. Label with tape neatly.
Split and label wires 3-12 individually:
From pins 13-22 that have already been grasped by the connector, pins 14 and 18 need to be split, separated and labeled. The other pins can be taped off together out of the way.
 Step 6: Crimping Wires with Connectors
We are up to adding crimp connectors to the individual wires. Most will just have their own connector, but others will have extra bits of wires spliced between them. We’ll do the easy ones first which is every wire except pin3 and pin4.
Strip back some rubber from the end, twist the exposed wiring into a single strand and then fold in half. Now place in the crimp connector. Of the two sections that fold over to grasp the wire, the larger should be squeezing the rubber insulation and the smaller should be squeezing the stripped wire. The video below demonstrates how to do this with just pliers
 Step 6: Creating and Crimping Additional Wires
Time to add in some spare bits of wire. We will need 6, and we will label them A-F. We will make them using the spare wire from pins 23-24 we split from the ribbon cable at the start.
Prepare and label 6 wires, 20cm (8 inches) long each. Both ends of each can be stripped and twisted ready for a connector.
Wires A and C can simply have connectors added to both ends:
Wire B can have one end twisted together with pin4 from the main ribbon cable. I used a little bit of heat shrink over the insulation to help hold the two wires together.
Crimp a connector onto one end of wire D. Now take the other end and twist it together with one of the ends of wire E. Crimp a connector to the junction.
Now take one end of wire F and twist it with the open end of wire E. Crimp them together with a connector.
Finally, twist together the open end of wire F with pin3 from the main ribbon cable and crimp them together in a connector. There should be a daisy chain from pin3 to F to E to D.
 Step 7: Connecting it All Together
We are ready to start plugging in all of the connectors into the plugs.
Take one of the 6pin black connectors, and starting at the arrow end, plug in:
- one end of wire C
- one end of wire A
- the single end of wire D
- pin 14
- pin 10
- pin 8
Each one needs to be pushed in far enough that the little tab appears in the little matching hole.
Each one needs to be pushed in far enough that the little tab appears in the little matching hole.
Take the 2pin connector and plug in:
- pin18 to the hole with the arrow
- the open end of wire B
These two plugs now go into the small PCB with the rotary encoder. The arrows face the reset switch side.
Now we will organise the other two 6pin connectors, which go into the large LCD panel PCB.
Take a connector, and starting with the arrow end, plug in:
- the pin3/wireF combo
- the pin4/wireB combo
- free end of wire C
- the wire E /wire F combo
- pin 12
Take the last 6pin connector and starting with the arrow end, plug in:
- wire A
- wire D /wire E combo
There should be no wires left except the unused pins 1-2 from the ribbon cable. Insulate these with tape to prevent disaster.
The first connector goes in the corner header, with the arrow facing the corner.
The second connector goes in the last header with the arrow facing the first connector.
The SDSL plugs in so the words TP3P are close to the arrow on the grey connector.
 Step 8: Adding the Connector For the Solidoodle End
Now we will add the connector to the other end of the ribbon cable. You may like to cut the cable down to a shorter length first. This is a 24pin connector for only a 22pin cable, so make sure the red striped pin1 is near the small arrow on the connector. Use a small vice to again push the cap on the plug, trapping the ribbon cable.
 Step 9: Solder the Header Pins to the Solidoodle Board
The Solidoodle only ships with a certain amount of headers, so we must solder in enough for our ribbon cable to connect. You will need to release the electronics from the frame by undoing the four hex screws in the corner.
For this step you have two options. The headers that come with the kit have a 90 degree bend so you can either bend them straight, or buy straight headers. I chose to simply bend the headers straight with some needle nose pliers.
Now comes the hard part. Ideally you will have a soldering iron AND solder braid on hand. The holes in the PCB where the header pins need to be inserted already have solder in them. Placing the pins will be a lot easier if the solder is removed to leave empty holes.
Solder braid can be used to suck up the existing solder like a sponge, as demonstrated in this video:
Push the headers into place and solder the pins neatly on the underside of the PCB.
 Step 10: Change Microcontroller and Flash Firmware
Replace the standard 644P microcontroller with the new 1284P from the kit. It actually has Marlin on it already, but the configuration is not set up for Solidoodle. Please note the direction of the notch on the 1284P. Be careful not to bend the pins sideways when removing the 644P and inserting the microcontroller.
Connect the ribbon cable to the headers with the red stripe for pin1 facing towards the centre of the PCB. Take extra care to line up the connector with the correct pins.
Powering on the printer yields instant results. The Panelolu will come to life immediately because Marlin is already installed on the 1284P. The configuration, however, is not suited to the Solidoodle so we still have to update the firmware. Note the 'Mendel' wording on the LCD.
I have previously set up the required firmware with the help of others on this board. The files and step by instructions are available here:
Once the firmware has been updated successfully, we are ready to test! After uploading the new firmware, you will need to disconnect and reconnect the power to see the changes. If the update was successful, 'Mendel' should be replaced by 'Solidoodle' on the main LCD screen:
 Step 11: Printing a Case and Mount
A case needs to be printed to hold the new hardware. Such cases already exist on Thingiverse, but I found some of the parts weren't quite right. The other problem was that the official case was designed for mounting onto a Mendel printer, not a Solidoodle.
Therefore I decided to design a custom mounting solution that used new parts with the two main pieces of the official case. The design utilises the metal case of the Solidoodle, and left over magnets from making Ian's dial indicator mount. If you don't have a case, then get one. It makes the bed heat faster, prevents the edges of prints cooling and lifting, and looks professional.
If there is enough demand, I'll design a magnet mount for the bare frame version.
All of the files are on thingiverse:
Print the front and back cases, as well as the new knob file.
Use the screws from the Panelolu kit to secure the SD card reader and rotary encoder PCB. I had to modify two parts post printing as pictured. One part had to be snapped off as it fouled the ribbon cable, and the other needed filing as it was too tall.
Update: The thingiverse files have been updated slightly to fix the problems with the original case. The part needing to be snapped off has been removed and the ribbon stay has been narrowed. One corner has also been extended to create space for a toggle switch. These updated files can be found on the original thingiverse link.
Push on the knob. This should be a tight fit and may require trimming with a sharp knife to the opening to get the right balance between fitting and tight. Some users have found that their Panelolu kit has a different sized rotary encoder and the knob in the thingiverse link does not fit. Fortunately, other Panelolu knob designs exist on thingiverse, and most users have found one that is a suitable size for their kit.
Print the magnet base mount and use a small vice to push in 7 rare earth magnets (1/4inch x 1/4inch). Rotate the stl so the flat side is down. Select whether you are mounting your Panelolu on the side or the top of the case and print the appropriate adapter piece. Rotate the stl so the flat side is down.
Print the locking pin and use it to hold the two mount pieces together. This image shows the side mount assembly:
Use the hex bolts, washers and nuts to close the front and back case pieces together. Fix the top/side mount adapter in place behind the rotary encoder with the hex screw and a (longer) self tapping screw.
Due to an error early on in my wiring, my ribbon cable is a bit shorter than ideal. Others following this guide should have more ribbon cable length and hence more flexibility in mounting position.
Here is the Panelolu mounted with the side mount piece:
And in this example the top mount piece: