DP2 - Da Pimp 2 Assembly Instructions

DP2 is a extremely portable battery tester / desulfator / charger. These are the instructions for assembling a DP2 kit. Kits or fully assembled units are available for sale through the Holy Scrap Store. More up to date information is available on the DP2 Page.

Step 1: Open the Enclosure

Step 2: Cut Open the Components Bag

Step 3: Empty Bag Contents

Step 4: ​Place and Solder 28 Pin DIP Socket [U1]

Note:The small impression must be near the right edge of the circuit board.

Step 5: Attach the Fuse Holders to the Fuse

Step 6: Place and Solder the Fuse [F1]

Step 7: Cover the 2-pin Jumper Headers With Their White Covers

Step 8: Place and Solder the Jumpers [J2, J3]

Step 9: Place and Solder 7 Segement Display [D1]

Step 10: Place and Solder DC Barrel Jack [CONN1]

Step 11: Place and Solder AC Power Cord Receptacle [CONN2]

Step 12: Place and Solder Decoupling Capacitors [C4, C5]

Note:Orient the minus sign on capacitors to the bottom of the circuit board

Step 13: Place and Solder the Bridge Rectifier [U3]

Note:Orient the + sign towards the top of the circuit board

Step 14: Place and Solder 300 Ohm Resistors [R1, R2, R3]

Step 15: Place and Solder 25k Ohm Resistor [R4]

Step 16: Place and Solder 470 Ohm Resistor [R5]

Step 17: Squeeze Your Microcontroller Leads to Fit the IC Socket [U1]

Note: I like to hold the chip at a slight angle and gently press the leads in

Step 18: This Is the Amount of Curve You Are Looking for on the Leads.

Step 19: Place the Microcontroller Into the DIP 28 Socket [U1]

Note:The small divot in the chip should be facing the right side of the board

Step 20: Place and Solder the 7805 5v Regulator [U2]

Note:Orient the text side towards the lower circuit board

Step 21: Step 21: Place and Solder the 9v Protection Diode [D2]

Note:Orient the black line on the diode to match the silkscreen (left side)

Step 22: Place and Solder the Slide Switch [S1]

Step 23: Place and Solder Large Charge Capacitors [C1, C2, C3]

Step 24: Place and Solder Large Black Rocker Switch [S2]

Note:Match the 0 / 1 orientation on the silkscreen.

Step 25: Clip Battery Lead to 2" in Length. Twist and Tin the Leads.

Step 26: Solder 9v Battery Cap

Note:Left is negative (black), Right is positive (red) as the silkscreen indicates.

Step 27: Nsert Assembled PCB Into Enclosure

Note:Align cable plug holes then press hard on opposite side of PCB for secure fit. It will be a little uneven as the retailer I've been buying enclosures from has changed models

Step 28: Connect 9v Battery

Comments

[dchang0]

Hi, everyone--

First of all, I am not Mikey. I am the creator of DIMP 1 and DIMP 2 based on Mikey's DA PIMP 2. You can find DIMP 1 and DIMP 2 instructions here on Instructables.

I have modified Mikey's DA PIMP 2 into Revision 2 to swap out the discontinued Schurter rocker switch with a widely-available OMRON rocker switch.

Everything is released free of charge to the Open Hardware community including the gerber files so you can order your own PCBs from anywhere you like.

I did this for free, so please do not yell at me if it doesn't work. Instead, check the included schematics and the gerber files to make sure they look like they will work BEFORE you order anything.

Also, I am not providing any tech support for this project at all. If you can't figure it out, please ask other users here for assistance and work together as a community in the comments section. Between what Mikey provided and I compiled together, you have everything you need to figure out what to do.

The whole DA PIMP 2 Rev. 2 project is here:

dchang0/dapimp2: Mikey Sklar's DA PIMP 2 reworked into Revision 2 to use an OMRON rocker switch instead of the discontinued Schurter rocker switch. (github.com)

[bricego]

Thanks dchag0 and to Mikey for these designs. I now plan to build a DA PIMP Rev. 2 here in the UK. I note the unit works at 110V or the 240V supply we have in the UK but that the output current here will be roughly twice. Should I change some of the components to compensate for this? I'm concerned that the current being much higher will cause other issues.

[kcassella]

Hello,
I had to put a 10k pullup resistor on pin 1 (reset) on the atmega48. It would stay in reset. Other than that, the dapimp works very good.

[dchang0]

Thanks very much for letting me know!
I'll double check the schematic and layout to see if I caused the problem with the reset. I might even add a spot to insert a 10k pullup resistor.

UPDATE: I checked the schematic and layout and I don't see any obvious problems that would cause the AtMega48V to remain in reset. Pin 1 Reset only goes to pin 5 on the 10-pin J1 connector and nothing else.
I'll wait for more reports about the need for an external pull-up resistor before adding a spot for one.

[kcassella]

The reset is active low. I believe letting the pin float may causes issues. In my case, it did. Using a pullup resistor ensures there is no issue.

[dchang0]

Thanks. I'm used to the AtMega48V-10PU's internal pull-up resistors being turned on when I receive them (from Mouser). Let me check the user manual on how to turn them on and off.

UPDATE: I searched the user manual for "internal pull" which brings up several pages that talk about the internal pull-up resistors and what they do to the pins, but so far I do not see specific instructions on how to turn the internal pull-up resistors on or off. It's gotta be in the user manual, but I am not using the right search keywords.

UPDATE 2: It's probably the same procedure as for the AtMega328 used in Arduino boards. There are plenty of YouTube videos on how to turn on the internal pull-up resistors for Arduinos. You could probably affix a temporary external pull-up to stop the RESET from RESETing, then run a sketch to turn on the internal pull-up and remove the external pull-up.

There's a code example near the bottom of this tutorial:

Arduino Internal Pull-Up Resistor Tutorial - Bald Engineer

[kcassella]

Thanks for looking further into the pullup resistor. I know how to use the pullup function in the Arduino IDE. But I don't have your program to load into the Arduino IDE.
But all is fine, I just put a 10k resistor on the back side of the board from pin 7 to pin 1.
Thanks again.

[dchang0]

Thank you for your input--you've been a great help to this project!

Mikey's original source code in C is here if you ever need it.

dapimp2/da_pimp2.c at main dchang0/dapimp2 (github.com)

I am not sure if it works without modifications in the Arduino IDE. It should, but I don't really know. I use WinAVR instead.

[kcassella]

You are welcome. Thanks for the C code.
Thank you for the great project.

[kcassella]

Hello,
Looks like the gerber files are showing you also changed switch 1 (S1) from a SPST to a DPDT slide switch. Also, S1 got moved from being next to the caps to next to the rocker switch.
Just wondering why?
Thanks for a great project and tool.

[dchang0]

Hi, and thanks!

Re: S1 from SPST to DPDT: There's not any electrical reason to do so. Having more pins soldered to the PCB increases the mechanical sturdiness of the switch. Also, the DPDT version of the switch is generally easier to find in stock than the SPST version. I didn't want what happened to Mikey's DA PIMP 2 to happen, where a component became almost impossible to get.

Re: S1 moved next to the rocker switch: I had to do this due to the placement of the 9V battery, but the move also has the benefit of keeping the "user interface" compact. Anyone designing 3D printed cases will like that the switches are near the bottom and aligned with each other.

[kcassella]

Thank you for your quick reply.
Looks like Mouser has the parts I need.
Oh, I do have another question. How come you didn't use an atmega328 chip?

[dchang0]

I stuck with the original chip that the original designer, Mikey, used to minimize any chance of source code changes or different pin-outs.

[RandyH95]

Hello Da Pimp creator lol
My name is Randy Hartenstine and I purchased a Da pimp from you many years ago but never really used it because it doesn't seem to work right so I was hoping maybe you could help me fix it? My tractor battery went dead the other day but the da pimp wouldn't work right it kept saying it had 4.2 v on it and the meter said it was fully charged at 12.9 volts and if I turn on the display while charging it shows 17.7 volts sometimes and 20.1 volts other times. I know it might be hard to troubleshoot without seeing it but I can record a video with instructions from you on how to check it or whatever way you need to diagnose it. I could never get it to work right so I just didn't use it but I would like to use it if you can help me fix it....

Well, Thanks a lot for listening and I hope to hear from you soon
you can call me if you want at 904-349-3421 or email at [e-mail] or I can call you if you like
Thanks Randy

[RandyH95]

Ahhh! duh on me that makes sense simple-thanks!

[RandyH95]

Ok I replaced the 9v battery and I hooked up a dewalt 18v power tool battery which read 14.1 volts and the da pimp display shows zero! But, I noticed if i push up a little on the display switch it reads the current voltage of 14.1 volts so I guess the switch is faulty somehow! What can I do to fix that?

[RandyH95]

I guess i wud have to get a new switch but is it hard to replace?

[RandyH95]

Do you have any suggestions of do i just need to replace the unit? dang that really stinks but at least i think ive discovered the problem

[dchang0]

Randy:
The switch for the 9V battery is an ALPS SSSU012200.

You can buy them from Avnet for 24 cents each.

https://www.avnet.com/shop/us/products/alps-alpine...

To replace it you would need to desolder the old switch with a pencil soldering iron and desoldering wick/braid OR a desoldering suction bulb.

[sklarm]

Replace the 9v battery on Da Pimp.. That will fix the voltage read