Bill of Materials - Digi-Key Order Form

MegaSquirt Main Board v3.0

This BOM (bill of materials) is intended for reference only. Bowling and Grippo no longer sell partial kits directly, you must purchase MegaSquirt® from a distributor or reseller, who will normally provide the parts you need in a 'complete kit'.

Note: If you do not see a table of parts below, you must either add to your trusted sites, or allow 'active content' for this page (see the warning near the top of the browser window).

Quantities are as required for MegaSquirt, except where minimum quantities are required.(Note: the calculated total on this form may be higher than Digi-Key indicates because you may get some quantity discounts depending on your order size).

Click the clear button below if you need to clear any open orders with Digi-Key. Then press the 'back' icon to return to this site and start your order.

To order, complete the following five steps:

  1. Choose the configuration for your MegaSquirt® v3.0 main board. A number of components are optional for the v3.0 main board. In general, you should install all the components and select between them using jumpers (see the assembly guide for a description of the options). However, you may save some money if you know exactly what you want/need and won't be changing or upgrading later.

    The total for the options you have selected is:


    (You can 'select' and 'unselect' options to the right to see what effect it has on your total cost.)

    1. Basic components, (Required),
      This includes the items needed in every MegaSquirt® build. It does not include NOT enough components to build a working MegaSquirt® EFI Controller, you must add some of the components below.

    2. PWM flyback damping circuit, (Optional),
      The PWM flyback damping circuit is identical to that found on the flyback board daughter card, and is needed for low-impedance injectors that don't have resistors.

    3. Hall sensor/Coil(-) and/or VR sensor ignition trigger circuit, (Choose at least one),
      The Hall sensor/Coil(-) circuit is nearly identical to the ignition triggering on the V2.2 boards, and is suitable for Hall sensor, optical sensor, points, or coil negative terminal triggering. The VR sensor circuit is used to take the AC signal from a magnetic reluctor distributor directly, without an intervening module. You can install both and select between them with jumpers.

    4. IGBT high-current ignition driver circuit, (Optional),
      The IGBT high-current ignition driver can be used to control a single ignition coil, or some other high current device.

    5. Current limiting circuit, (Optional),
      The current sensing circuit allows for driver FET protection. The clamp current is set to ~14 amps. The current limiting circuit can be omitted if protection is not required or desired.

    6. Sockets for all ICs, (Optional),
      Additional sockets for remaining ICs (40-pin CPU socket is included in 'basic parts').

    7. Spare parts, (Optional),
      Spare FETs, voltage regulator, polyfuses, and crystal

    8. Cables, (Optional).
      External DB-37 connector and DB-9 cable for those who don't already have a harness, and PC/MegaSquirt cable.

  2. Choose the number of kits you want parts for:

    I want parts for MegaSquirt(s).
    (click outside box to update form)

    Verify that you have the quantities you want for each item below. You can change the quantities to any amount you want by typing numbers directly into the form.

  3. Then send your order to Digi-Key:

  4. You will be redirected to Digi-Key to verify your order, payment method, and shipping details. You can edit the quantities, etc. at that point as well, and also cancel your order if you wish.
    • If you are purchasing parts for MegaStim and/or the relay board, do not finalize your order. Return to the ordering page and complete steps 3 and 4 there.
    • If you are NOT purchasing parts for MegaStim or the relay board, check the quantities on the Digi-Key site, and proceed to the next step on this page.

  5. Click the 'finish order' button at the bottom of the Digi-Key page, and follow the instructions there. The order will not be complete until you have finished this step. You can re-do your order by returning to this page at any time before finalizing your details with Digi-Key.

Here are the other parts you'll need to build your MegaSquirt: Some MegaSquirt® Related Links:

PWM Idle Valve - If will be using a PWM Fast Idle valve (such as the IAC from Ford), then you will also need one TIP120 497-2539-5-ND, 65¢ each. You should use a mica insulator as well: 36-4724-ND, $2.13.

Wiring Harness - RS Autosport offers wiring harness kits for MegaSquirt® EFI Controller, with properly labeled and colored wires in appropriate sizes. You can find out more at their website.

LMB EAS-300 case - you can purchase the case from HdB Electronics (650-368-1388) in single unit quantities. Your choice of natural aluminum or black anodized. This is where the Group Buy orders for the case were placed.
Or you can get the EAS-300 Enclosure [style 4006 - 4.124" x 1.582" x 6" w/ heavy radiused (H) ends] at:
You might also try Fry's, they have one that measured 6 x 4.17 x 1.56. It costs $15.95.

Nylon Screws - 4/40 - Digi-Key P/N H550-ND - 0.0926ea. & Nylon Nuts - 4/40 - P/N H616-ND - 0.105ea. You need 8 of each, but there is a 100 minimum quantity for each from Digi-Key. You can try locally, look for them in hobby shops that sell radio control hardware.

MegaSquirt Site

MegaSquirt Forums

MegaSquirt FAQ


* You can also use the MAX232 IC from TI (296-6940-5, $0.85), if you do this, you must change C26,C27,C28,C29 to capacitor 1.0µF 50V (399-4329-ND, $0.22ea. or 399-4390-ND $0.53ea.)

Click here to go back to the MegaSquirt® FAQ
Thanks to Eric Fahlgren and Perry Harrington for the Javascript and other great ideas.

MegaSquirt® and MicroSquirt® controllers are experimental devices intended for educational purposes.
MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.
©2005, 2017 Bruce Bowling and Al Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks. This document is solely for the support of MegaSquirt® boards from Bowling and Grippo.