diff --git a/README.md b/README.md
index 57cd0d6..f7c59ae 100644
--- a/README.md
+++ b/README.md
@@ -136,6 +136,9 @@ Test the prototype.
         will prevent ESP32 from booting
     [ ] ESP-32: won't boot when SD connected. Don't solder it at PCB v1.7
         it should be routed differently in newer release
+        Here is a possible SD card connection
+        Arduino->Examples->ESP32->SD_MMC_Test
+        https://github.com/espressif/esp-idf/blob/master/examples/storage/sd_card/README.md
     [x] I2C resistors increased 470->2.2k
     [ ] GPDI series C=100nF to each differential line.
     [x] reliable shutdown (D11=RED LED, R4=4.7k)