1 [[!meta title="EasyTimer"]]
4 This board provides two programmable timer-based pyro channels with tilt
5 limits. It is the same size and shape with the same connector layout as
6 our [EasyMini](../EasyMini) flight computer.
8 The IMU used is the same as on TeleMega and EasyMega, allowing acceleration
9 based launch detection, and gyro-based tilt limiting. This means it's
10 possible to configure a pyro event for some amount of time after launch,
11 or after motor burnout, etc, with the possibility of locking out each event
12 if the rocket is tilted too far away from vertical.
14 For projects that require staging or air starts, EasyTimer is a low-cost
15 alternative to use of our more expensive products, while retaining the safety
16 aspects of tilt-limiting.
18 EasyTimer firmware and associated configuration software is part of the
19 [AltOS](../AltOS) suite.
21 Photos of the first production unit (the current version 2 looks nearly
24 <a href="v1/easytimer_v1_top.jpg"> <img src="v1/easytimer_v1_top-thumb.jpg"></a>
25 <a href="v1/easytimer_v1_smt.jpg"> <img src="v1/easytimer_v1_smt-thumb.jpg"></a>
27 EasyTimer v2 is available for sale now at
28 [Bdale's web store](http://shop.gag.com/flight-computers/easytimer.html)
29 and from Altus Metrum distributors.
35 * Two programmable flight state event and timer-based pyro channels with
37 * USB for configuration
38 * Designed for use with batteries from 3.7 to 12 volts
39 * 1.5 x 0.8 inch board
43 There is a single manual for EasyTimer and most other Altus Metrum products,
44 which is available in [html](../AltOS/doc/altusmetrum.html) and
45 [pdf](../AltOS/doc/altusmetrum.pdf) formats.
47 This board was designed using lepton-eda and pcb-rnd.
49 The hardware design files are available from
50 [git.gag.com](http://git.gag.com) in the project
51 [hw/easytimer](http://git.gag.com/?p=hw/easytimer;a=summary).
53 For those who don't have ready access to the gEDA suite, here are pdf snapshots
54 of the files for current production PCB version 2 in more easily readable form:
56 * [schematic](v2/easytimer-sch.pdf)
57 * [pcb artwork](v2/easytimer-pcb.pdf)
58 * [bill of materials](v2/partslist.csv)
60 ## Previous Versions ##
62 All versions of EasyTimer have the same user-visible features and
63 specifications, except that v1 did not contain on-board flash data storage
64 making post-flight analysis .. "challenging". Other than that, the
65 differences are primarily in the choice of processor and sensors, which
66 is driven by availability.
68 Here are the schematics, artwork, and bill of materials for version 1:
70 * [schematic](v1/easytimer-sch.pdf)
71 * [pcb artwork](v1/easytimer-pcb.pdf)
72 * [bill of materials](v1/partslist.csv)