diff --git a/lambda-gen-s3-url.py b/lambda-gen-s3-url.py
index ff1f83a..c185e34 100644
--- a/lambda-gen-s3-url.py
+++ b/lambda-gen-s3-url.py
@@ -15,7 +15,7 @@ def lambda_handler(event, _context):
     filename = event['filename']
 
     try:
-        url = s3.generate_presigned_put(BUCKET, filename)
+        url = s3.generate_presigned_post(BUCKET, filename)
         print("Got presigned URL: %s", url)
     except ClientError as e:
         print(e)
diff --git a/led_control.py b/led_control.py
index 35bde9b..9c9a7a9 100644
--- a/led_control.py
+++ b/led_control.py
@@ -11,20 +11,20 @@ import requests
 from awscrt import mqtt
 from awsiot import mqtt_connection_builder
 
-DEBUG = 0
+DEBUG = 1
 
 UUID = f"cloudprog-{uuid.uuid4()}"
 
-ENDPOINT = ""
-CA = ""
-CERT = ""
-PRIVKEY = ""
+ENDPOINT = "a1io7cze9x1oli-ats.iot.us-east-1.amazonaws.com"
+CA = "rootCA.pem"
+CERT = "cert.crt"
+PRIVKEY = "privkey.pem"
 
-LED_TOPIC = ""
+LED_TOPIC = "cloudprog/hw4/team02/led"
 
 # https://aws.amazon.com/tw/blogs/iot/securely-ingesting-large-sized-payloads-from-iot-devices-to-the-aws-cloud/
-S3_UPLOAD_TOPIC = ""
-S3_URL_TOPIC = ""
+S3_UPLOAD_TOPIC = "cloudprog/hw4/team02/s3/upload"
+S3_URL_TOPIC = "cloudprog/hw4/team02/s3/url"
 
 FORMAT = "jpg"
 
@@ -95,7 +95,7 @@ def led_control(light):
 def parse_s3_url_payload(payload):
     data = json.loads(payload.decode())
 
-    put_presigned_s3_url(data["url"], take_picture())
+    post_presigned_s3_url(data["url"], take_picture())
 
 
 def take_picture():
@@ -106,8 +106,8 @@ def take_picture():
     return img.tobytes()
 
 
-def put_presigned_s3_url(url, img_bytes):
-    res = requests.put(url, data=img_bytes)
+def post_presigned_s3_url(url, img_bytes):
+    res = requests.post(url, data=img_bytes)
     print(f"Put to S3. status code: {res.status_code}")
     return res