my first hardware project: an offline cashu wallet on an esp32.
generate ecash, send it to the esp32 via bluetooth, esp32 decodes the ecash into individual proofs, pick any proof and display it as a QR code for redemption.
the esp32 never touches the internet. completely airgapped. just receives tokens, holds them, and displays cashu tokens.
erik
npub1zq…fcqrs
2025-12-05 01:40:59 CET
Author Public Key
npub1zqsu3ys4fragn2a5e3lgv69r4rwwhts2fserll402uzr3qeddxfsffcqrsSeen on
wss://nostr.winePublished at
2025-12-05 01:40:59 CETEvent JSON
{
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"pubkey": "1021c8921548fa89abb4cc7e8668a3a8dcebae0a4c323ffeaf570438832d6993",
"created_at": 1764895259,
"kind": 1,
"tags": [
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],
[
"r",
"wss://nostr.wine/"
],
[
"r",
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],
[
"r",
"wss://relay.damus.io/"
],
[
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]
],
"content": "my first hardware project: an offline cashu wallet on an esp32.\n\ngenerate ecash, send it to the esp32 via bluetooth, esp32 decodes the ecash into individual proofs, pick any proof and display it as a QR code for redemption.\n\nthe esp32 never touches the internet. completely airgapped. just receives tokens, holds them, and displays cashu tokens.\n\nhttps://blossom.primal.net/3f28a048378858a7de8bf498e253298ab32c16512ed10918bec6a8fa48739580.mp4 ",
"sig": "b37696f5e76ba5b1b761ae6a06d235f40e92dcd3018843f17a8fbccf9d41b436023d2141ad64cb94c96d063dfb5ceca4b8d1b0eb105f651b422cdf168a449e07"
}