# mohan-bee - IMG20260730132508.jpg Channel: #contributor Source: https://discord.com/channels/1233487248129921135/1532296389592219681 Started: 2026-07-30T07:58:48.651000+00:00 Last activity: 2026-08-02T22:13:46.233000+00:00 ## mohan-bee — 2026-07-30T07:58:47.969000+00:00 Got this one today!!! super cool Attachment: IMG20260730132508.jpg — https://community.tscircuit.com/media/1532296388698701876 Attachment: IMG20260730122614.jpg — https://community.tscircuit.com/media/1532296389361664101 ## mohan-bee — 2026-07-30T07:59:46.498000+00:00 https://tscircuit.com/mohan-bee/keychain ## mohan-bee — 2026-07-30T08:05:59.650000+00:00 <@757706909351411845> <@&1420812538421051555> ## Vanuan — 2026-07-31T12:37:46.626000+00:00 Does it light up? ## mohan-bee — 2026-07-31T12:43:24.526000+00:00 yeaa.. not that bright.. ## mohan-bee — 2026-07-31T12:43:31.810000+00:00 probably I need to change the battery ## Vanuan — 2026-07-31T15:56:45.623000+00:00 I wonder if there's any difference between shorting using finger or shorting using some jumper wire. So maybe it's not a battery, but the high resistance of your skin ## Vanuan — 2026-07-31T16:01:03.726000+00:00 Maybe some small touch sensitive switch components would be more reliable, though kind of reduces the coolness factor ## Vanuan — 2026-07-31T16:11:13.994000+00:00 TTP223 looks like a standard solution Attachment: Screenshot_20260731-171036.png — https://community.tscircuit.com/media/1532782702351356126 ## mohan-bee — 2026-07-31T16:11:58.855000+00:00 yea i literally had this thought after placing order ## mohan-bee — 2026-07-31T16:12:46.495000+00:00 okay then will soldering those copper pads .. work ?? ## Vanuan — 2026-07-31T16:13:31.986000+00:00 The alternative is some mechanical jumper wire you put on the key chain. Makes you imagine being a car thief 🤭 ## mohan-bee — 2026-07-31T16:13:46.024000+00:00 lol ## Vanuan — 2026-07-31T16:16:14.523000+00:00 Soldering one end of the wire with some duct tape on the other pad maybe 🤔 ## Vanuan — 2026-07-31T16:17:01.120000+00:00 Or some pretentioned spring ## mohan-bee — 2026-07-31T16:17:14.274000+00:00 hmm... wil do ## Vanuan — 2026-07-31T16:25:49.767000+00:00 [attachment] Attachment: image0.png — https://community.tscircuit.com/media/1532786375387250822 ## Vanuan — 2026-07-31T16:38:47.622000+00:00 Just for fun, some calculations if you want to replace the battery Attachment: Screenshot_20260731-173750.png — https://community.tscircuit.com/media/1532789637871960195 ## Seve — 2026-07-31T16:39:25.171000+00:00 capacitive touch would be cool ## Vanuan — 2026-07-31T16:55:59.682000+00:00 Chip starts from $0.04 but requires aux components Attachment: 737b9dceee46c724e100af711c312f900697387b.jpg — https://community.tscircuit.com/media/1532793966628442243 ## Vanuan — 2026-07-31T17:01:37.363000+00:00 [attachment] Attachment: sddefault.jpg — https://community.tscircuit.com/media/1532795383263006761 ## Vanuan — 2026-07-31T17:05:51.826000+00:00 MOSFET might be an even better solution. Short the gate pin with your skin, deliver full power to the led ## Seve — 2026-07-31T17:06:09.738000+00:00 yea that's cool ## Vanuan — 2026-07-31T17:07:29.638000+00:00 I assume the capacitive sensor is for use cases where the switch is hidden behind a plastic case. This is the opposite of that ## mohan-bee — 2026-08-02T09:44:44.762000+00:00 like you said hand is the problem ## mohan-bee — 2026-08-02T09:44:47.228000+00:00 check this now !!! did some alteration Attachment: VID20260802151332.mp4 — https://cdn.discordapp.com/attachments/1532296389592219681/1533410225405562971/VID20260802151332.mp4?ex=6a710bcf&is=6a6fba4f&hm=4d730ce3ac81e2a6b51ab99e9755eaa87428e296aad30d8e9182fa8c8ea97b26& ## mohan-bee — 2026-08-02T09:45:10.367000+00:00 i burned a led . By direct supply hehe ## mohan-bee — 2026-08-02T09:45:54.272000+00:00 i am worst in soldering 😖 ## mohan-bee — 2026-08-02T09:46:06.718000+00:00 now added a 3v coin cell at the back ## Vanuan — 2026-08-02T10:20:21.877000+00:00 Now you need some OVP and properly calculate the value of those resistors 🙃 . Though 220k seems to be plenty ## Vanuan — 2026-08-02T10:22:26.226000+00:00 You used bench power supply instead of battery? ## mohan-bee — 2026-08-02T10:22:45.548000+00:00 no i attached a coin cell at the back ## mohan-bee — 2026-08-02T10:23:06.572000+00:00 i bought this module ## mohan-bee — 2026-08-02T10:23:07.173000+00:00 [attachment] Attachment: image.png — https://community.tscircuit.com/media/1533419872338575380 ## Vanuan — 2026-08-02T10:23:07.694000+00:00 Shouldn't have burnt out ## mohan-bee — 2026-08-02T10:23:25.225000+00:00 no i just kept the 9v directly on the led terminla ## mohan-bee — 2026-08-02T10:23:33.648000+00:00 so that burned only one led where i kept ## Vanuan — 2026-08-02T10:23:47.849000+00:00 Where 9v is coming from ## mohan-bee — 2026-08-02T10:23:57.273000+00:00 no that is a seperate battery ## mohan-bee — 2026-08-02T10:24:12.145000+00:00 and then i used this module at the back add a 3v coin cell ## mohan-bee — 2026-08-02T10:24:14.513000+00:00 soldred ## mohan-bee — 2026-08-02T10:24:18.136000+00:00 everything works ## mohan-bee — 2026-08-02T10:24:20.097000+00:00 fine now ## mohan-bee — 2026-08-02T10:24:24.412000+00:00 only without hand ## Vanuan — 2026-08-02T10:26:43.088000+00:00 Yeah, 9V is too much, red led requires around 2V. ## mohan-bee — 2026-08-02T10:26:52.276000+00:00 yea ## Vanuan — 2026-08-02T10:33:04.567000+00:00 Lower resistance make them brighter. Though would make battery life shorter ## mohan-bee — 2026-08-02T10:33:57.426000+00:00 yea that's ok for .. i do have a switch .. so i think managable .. ## Vanuan — 2026-08-02T10:35:51.862000+00:00 So BS_08_B2AA010_R is not used here: https://tscircuit.com/mohan-bee/keychain ? ## mohan-bee — 2026-08-02T10:36:45.538000+00:00 no that was in the older version ## Seve — 2026-08-02T16:43:01.480000+00:00 haha that looks super bright ## Seve — 2026-08-02T16:43:06.531000+00:00 is there a resistor? ## mohan-bee — 2026-08-02T22:13:46.233000+00:00 Yes