The Eggtimer Apogee - A Very Simple Apogee-Deployment Altimeter

[cerving]

Try setting the COM port to COM1-COM4, I usually use COM2. Windows might complain about it, but ignore it...

The serial test is primarily designed to check the baro sensor, you can also do the same thing with a vacuum test, which actually is a better test because it tests everything. Don't use a live BP charge, of course... although you can use an ematch if you test outdoors and make sure it's at least 2' from you or anything else (testing it indoors will probably get you the stink eye from your significant other, and possibly set off your smoke alarms).

 

[_kestrel_]

Try setting the COM port to COM1-COM4, I usually use COM2. Windows might complain about it, but ignore it...

The serial test is primarily designed to check the baro sensor, you can also do the same thing with a vacuum test, which actually is a better test because it tests everything. Don't use a live BP charge, of course... although you can use an ematch if you test outdoors and make sure it's at least 2' from you or anything else (testing it indoors will probably get you the stink eye from your significant other, and possibly set off your smoke alarms).

Just tried changing to COM2, Windows accepted the port change with no fuss. Buzzer again starts yelling at me the second that TX and GND are connected. This is before I apply power to the Apogee with the screw switch. It does this whether the battery is connected or not. I'll try the vacuum test later tonight.

Edit - ...and thanks for the speedy reply.

 

[cerving]

Are you using the Eggtimer cable or another cable? It should look something like this.

 

[_kestrel_]

Using the Eggtimer cable (USB-TTL Cable). Nothing shows up in PuTTY, just a blank screen. Does the Apogee buzzer normally sound when connected via USB? It is a continuous buzz, not the startup beep.

 

[cerving]

No, it should not, however the buzzer and the TX line share a processor output pin but normally the signals are different so you won't get a serial output if the buzzer is turned on and you won't get an audible buzzer output from the short 9600 baud data pulses. Do you have the WHITE wire connected to the TX pin and the BLACK wire connected to the GND pin?

 

[_kestrel_]

Yes - the buzzer sounds when the White wire is attached to TX and the Black wire is attached to GND.

 

[cerving]

My guess is that something is wrong with your cable and it's providing power (it should not, that's an input to the cable's serial chip). Do you have other Eggtimer kits that you can use to test it with? If not, get a small paperclip and short the green and white pins, plug it into your computer, start Putty at 9600 baud, and see if you get characters on the screen when you type. If you do not, it's a bad cable.

 

[cerving]

BTW, we've posted an advisory on the Apogee, see https://www.rocketryforum.com/threads/advisory-on-the-eggtimer-apogee.163233/ . Basically, we recommend that you use only a #2 Phillips screwdriver to actuate the screw switch; smaller ones (such as a #0, which is technically too small for the screw) can accidentally contact the side of the screw and short other components on the board. Using the proper screwdriver prevents this from happening.

 

[_kestrel_]

When I short Green to White, the Com port shows an error in Device Manager and PuTTY won't connect.

Bad cable?

 

[cerving]

PM me and we'll see about getting you a replacement cable.

 

[_kestrel_]

Update on the Apogee - vacuum testing was successful! I wired a incandescent christmas tree light up to the output and vacuum tested in a jar. It lit up shortly after removing the vacuum hose and beeped out an altitude.

Thanks Cris for making a kit that even a soldering novice can get together and make work!

 

[Scott231]

I've been trying to use the Apogee with a mini Wifi switch to no avail. Using the Red for positive and black for common as noted by H. Craig Miller.
Here is my wiring diagram:

With the above diagramed wiring, when I connect to the Wi-Fi switch and input the code, the e-match immediately fires. Cris has a theory on why but I will defer to him to confirm.

 

[Rocketless]

Has anyone used the Eggtimer apogee mounted in a nose cone but wired under the laundry into the deployment charge in the motor??
If you anchored the match wire into the shock cord just out of the motor mount and used a loose removable connector in the wire to allow for the wire to separate from the nose cone, would that work??
Just thinking out loud

 

[cerving]

If the intent is to let your motor delay long and use that as a backup, it should work, provided that the charge well for the motor has enough room for both the powder and an ematch. I'm not sure that either AT or CTI give you a large enough charge well for that, however.

I HAVE run wires down from the nose cone to a separate charge well mounted on the payload bay side of the AV bay, you don't really need a disconnect. The wire is either going to come out with the laundry or just stay in the payload bay (if your break is on the AV bay side). I actually have a MD 38mm with a TRS in the nose, both wires run through the main chute payload bay. The main wire ran directly to an ematch in the charge well of the main side of the AV bay, the drogue wire was twisted around two brass rods that went through the length of the empty AV bay, on the drogue side of the AV bay the ematch was twisted around the rods. It worked fine.

 

[OverTheTop]

If you are mounting charges on different sections than the electronics you need to consider what happens when the two units separate. Make sure there are no unburnt charges when everything gets to the ground. You don't want unexploded energetics laying on the ground for any random person to pick up.

 

[ghostfather]

I've used a centrifuge capsule as charge well often enough, which can hold 1-2 grams of black powder, as the capsules come in different sizes. With a long enough e-match wire, it can be below the parachute, and I don't worry about it being damaged, as it is a disposable single use solution.

Some companies sell them as charge canisters including the e-match (Apogee used to). I make them myself. I ordered a bag of 500 centrifuge capsules for a few bucks, which should last me quite a while. Make a hole in the point of the capsule, thread the wires of the e-match through, and seal with a dab of hot glue. I give it a wrap of tape as a secondary seal.
Never had the e-match wire break or lose a charge canister this way, as you don't want it falling somewhere and polluting the environment.

 

[beeblebrox]

I've been trying to use the Apogee with a mini Wifi switch to no avail. Using the Red for positive and black for common as noted by H. Craig Miller.
Here is my wiring diagram:
View attachment 464205
With the above diagramed wiring, when I connect to the Wi-Fi switch and input the code, the e-match immediately fires. Cris has a theory on why but I will defer to him to confirm.

1. Have you tested the apogee timer by itself to rule out a problem there?
2. Your circuit is wired wrong. you are applying power to the apogee altimeter all the time you are not switching anything with the mini switch (It replaces the battery input... I am currently waiting for a reply from Cris Irving as to whether the apogee can use a 2s battery or not (EDIT: it can't).... Since the mini switch has a 3.3v regulator I would figure that a 1s battery would work anyway, use a 250-500maH one. I have had excellent results with the apogee by itself with the little battery it comes with, sitting on the pad for more than an hour with no issues...
3. Use a tiny dip relay between the mini switch and the apogee if you have to use a 2s on the mini and a 1s on the apogee...
4. Use a DC-DC converter to get output to 3.7v. These are cheap from https://www.mpja.com/ $3.95 They weigh 11 grams .875" x 1.75" Output from 1.5v to 37v. Also available with a digital voltage readout. $8.95
https://www.mpja.com/LM2596-Step-Down-Adjustable-15-37V-DC_DC-Converter/productinfo/30148+PS/https://www.mpja.com/Adjustable-15-...ter-with-LED-Volt-Meter/productinfo/30149+PS/

 

[cerving]

You can ditch that entire circuit, the Mini Switch now comes with a regulator that will work with a 1S battery. If you have one shipped before June 2021, we will send you the parts necessary for 1S use (regulator and two caps)... just send us an email.

 

[Rocketless]

I've used a centrifuge capsule as charge well often enough, which can hold 1-2 grams of black powder, as the capsules come in different sizes. With a long enough e-match wire, it can be below the parachute, and I don't worry about it being damaged, as it is a disposable single use solution.
View attachment 471581
Some companies sell them as charge canisters including the e-match (Apogee used to). I make them myself. I ordered a bag of 500 centrifuge capsules for a few bucks, which should last me quite a while. Make a hole in the point of the capsule, thread the wires of the e-match through, and seal with a dab of hot glue. I give it a wrap of tape as a secondary seal.
Never had the e-match wire break or lose a charge canister this way, as you don't want it falling somewhere and polluting the environment.

did you order the 1.5 ml capsules??

 

[beeblebrox]

Has anyone used the Eggtimer apogee mounted in a nose cone but wired under the laundry into the deployment charge in the motor??
If you anchored the match wire into the shock cord just out of the motor mount and used a loose removable connector in the wire to allow for the wire to separate from the nose cone, would that work??
Just thinking out loud

That could work, but I mount it low in the rocket below my ejection baffle...just have a separation joint to load the charge well (I made the device into a removable pod to set it up for flight...)

 

[Zbench]

I just posted the process I used to mount the Apogee in the nose cone of a rocket I'm building in the Techniques subforum. I thought folks might like to see what it looks like assembled into a nose cone. You can see it here.

 

[ROCKETDAWG]

This is what I'm seeing in PuTTY.
Vacuum test was successful.
Doesn't look like other screen shots.
Altitude is correct, but no 104.

 

[ROCKETDAWG]

This is what I'm seeing in PuTTY.
Vacuum test was successful.
Doesn't look like other screen shots.
Altitude is correct, but no 104.

Crickets

 

[Zbench]

I’ve not had good luck with Putty and Eggtimer products. You might try Tera Term, also a free terminal emulation program

 

[sl98]

I’ve not had good luck with Putty and Eggtimer products. You might try Tera Term, also a free terminal emulation program

I also use Tera Term for my multitude of Eggtimer products.

 

[sl98]

Crickets

Have you tried emailing Cris at [email protected]? Cris is super responsive and helpful.

 

[Buckeye]

I’ve not had good luck with Putty and Eggtimer products. You might try Tera Term, also a free terminal emulation program

PuTTY won't recognize my serial ports or the EggTimer USB cable, no matter what I do. TeraTerm has no troubles.

 

[cerving]

Did you load the driver from Prolific's web site? Windows WILL recognize the cable, but their driver doesn't work.

I also recommend changing the port to COM2, Windows will complain about that too but just ignore their "error" message.

 

[cerving]

Regarding the junk from the Apogee on Putty, it looks like either the wrong driver, or the wrong settings, but it could be a bad cable too (although that's rare). I have seen random junk on the screen when the cable is connected before the Apogee is powered on... but if you power it on you should always get the startup diagnostics sequence, and the screen should go quiet afterwards.

 

[boatgeek]

I've just built an Apogee and ran into an issue during testing that was kind of surprising. I was doing the all-up test with the E-match. I'd forgotten to connect the E-match when I powered the Apogee up, so I waited until the beep-beep came on indicating no continuity and powered it off with the screw switch. The battery was still connected. I connected the E-match to the outputs and it fired immediately. Another E-match connected before powerup fired just fine using the vacuum cleaner test.

I'm definitely going to short the terminals on the Apogee before connecting charges in the future to make sure that there's no residual power in the unit. Is this something that indicates an assembly error that I should try to track down?